AN ABSTRACT OF THE THESIS OF
hICHARD STANLEY AHO
in
Title:
Fisheries
for the degree of Master of Science
presented on
June 15, 1976
A POPULATION STUDY OF THE CUTTHROAT TROUT IN AN
UNSHADED AND SHADED SECTION OF STR
Abstract approved:
Redacted for privacy
Jame D. H
A study of the coastal cutthroat trout (Salmo clarki clarki) was
conducted in an unshaded and shaded section of a small stream in
the Cascade Mountains of Oregon. The objective of this study was to
test the hypothesis that no differences existed between the trout popu-
lations in the two stream sections. Periodic sampling and tagging
were used to determine population levels, growth rates, and produc
tion.
Movement, diet, and prey-size selection were also investigated.
The unshaded section provided better habitat for trout than the
shaded section.
Trout of the 1973 through 1971 year classes were
approximately twice as numerous in the unshaded as the shaded area.
Estimated biornass of all trout was 12. 2 gIn-i2 in the unshaded and
6. 2 g/m2 in the shaded section during October 1 973.
Mean length
by year class was greater for trout from the unshaded than from the
shaded habitat.
From April 1973 to April 1974, estimated production
was 7. 5 g/rn2 in the unshaded and 2. 6 g/mn2 in the shaded section.
Recapture of tagged trout indicated little movement. Ninety percent
of trout observed 1 yr or longer after tagging were recaptured within
100 m of the tagging location.
The higher level of trout production in the unshaded section
was probably a result of a combination of factors including differences
in diet, abundance of prey, and water temperature. The consumption of
grazing insects and insects with several generations per year was
greater for trout captured in the unshaded than the shaded area.
A
more productive food resource is indicated in the unshaded habitat
by the greater abundance of multivoltine insects in the diet of trout
from this area. In the unshaded section, emergence traps captured
approximately twice the combined biomass of several insect groups
that were important in the trout dieL Because of higher water tern-
peratures, trout fry emerged earlier in the unshaded than the shaded
section. Earlier emergence probably provided an initial growth
advantage that was maintained throughout life of the trout.
No consistent relationship was found between trout length and
mean prey length. For sampled stomach contents of trout from the
unshaded and shaded habitats, mean length of prey ranged from 1 to 7
mm. In laboratory streams, three sizes of trout normally selected
the largest prey when allowed to choose from prey of three sizes.
Large prey utilized in the laboratory streams were approximately
three times longer than mean lengths of prey sampled from stomachs
of trout from the natural stream. This observation suggests that
few large prey were available to wild trout.
A Population Study of the Cutthroat Trout in
an Unshaded and Shaded Section of Stream
by
Richard Stanley Aho
A THESIS
submitted to
Oregon State University
in partial fulfillment of
the requirements for the
degree of
Master of Science
Completed June 15, 1976
Commencement June 1977
APPROVED:
Redacted for privacy
ociatp"Professor of Fisheries
in charge of major
Redacted for privacy
Head of Department of Fisheries and Wildlife
Redacted for privacy
Dean of Graduate School
Date thesis is presented
June 15, 1976
Typed by Opal Grossnicklaus for Richard Stan'ey Aho
ACKNOWLEDGEMENTS
I wish to thank many people who have assisted and provided
encouragement throughout this project. Foremost is Dr. James D.
Hall, my major professor, who had the original idea for this study.
Dr. Hall also participated in collection of data, provided invaluable
ideas during the analysis stage, and edited earlier drafts of this
thesis. Dr. Norman H. Anderson of the Entomology Department
provided space and equipment for the laboratory experiments.
Dr. Anderson, Mr. Kerry Kerst, and Mr. Ed Grafius shared their
knowledge of identification of aquatic insects. Encouragement was
provided by Dr. James R. Sedell and the entire I. B. P. crew through
their interest and participation in this study. Mr. Mike Passmore
assisted during collection of field dat4, and his ideas and efforts are
appreciated. Special thanks are deserved by Miss Gail Herlick
whose cheerful manner of assistance often boosted my morale.
The work reported in this thesis was supported by National
Science Foundation grant no. GB-20963 to the Coniferous Forest
Biome, Ecosystem Analysis Studies, International Biological
Program.
TABLE OF CONTENTS
INTRODUCTION
The Study Area
MATERIALS AND METHODS
Characteristics of the Study Sections
Population Estimation and Tagging
Mortality, Growth, and Production
1
3
6
6
6
Stomach Content Sampling
9
12
Prey Selection
14
RESULTS
Characteristics of the Study Sections
Population Size
Mortality, Growth, and Production
Movement
Diet
Prey Selection
17
17
19
24
28
32
37
DISCUSSION
40
LITERATURE CITED
50
APPENDICES
LIST OF FIGURES
Page
Figure
1.
Maps of the study area and location within the state
of Oregon.
2.
Population size and survivorship by year class from
April 1973 to October 1974.
3.
5.
6.
8.
25
Terrestrial component by weight of the trout diet
during 1973.
34
Functional group components by weight of the trout
diet during 1973.
35
Combined contribution by weight of immature stages
of Chironomidae and Baetis in the trout diet during
1973.
7.
20
Growth curves by year class from April 1973 to
October 1974.
4.
4
36
Mean prey length and trout length for three dates
during 1973.
38
Selection of three sizes of prey by trout during
laboratory experiments.
39
LIST OF TABLES
Table
1.
2.
3.
4.
Page
Physical characteristics of the unshaded and shaded
study sections during Septembe1973.
17
Methods used for best estimates of population size
from April 1973 to October 1974.
23
Estimated biomass (g/m2) in the unshaded and shaded
study sections during October 1973 and October 1974.
23
Annual instantaneous mortality (i) and annual mortality
(a) rates by year class from October 1973 to October
1974.
24
Daily instantaneous growth rates of tagged and untagged
trout during 1973.
27
Daily instantaneous growth rates of trout in the unshaded
and shaded study sections during 1973.
27
Estimated production by year class in the unshaded and
shaded study sections from April 1973 to April 1974.
29
8.
Movement of trout from March to November 1973.
30
9.
Movement of trout tagged for one or two winters before
recapture during July and August 1974.
31
5.
6.
7.
/
LIST OF APPENDICES
Page
Appendix
A
B
C
D
E
F
G
H
Tagging sites and numbers of trout tagged during 1972
and 1973.
55
Method employed to correct mark-and-recapture
estimates.
56
Length frequency distributions for tiout captured in
the unshaded and shaded study sections during 1973.
62
Evaluation of flushing method of stomach content
sampling.
64
Volume of initial stomach contents remaining after
increasing intervals of time.
65
Weekly mean water temperatures for the unshaded
and shaded study sections during 1973.
66
Estimates and data for the removal method of estimation from April through October 1973 and for October
1974.
67
Comparison of weight prediction equations by method
of Ostle (1963).
68
/
I
1973.
J
K
L
'I
Weight prediction equations from data collected during
68
Length frequency distributions of trout in the unshaded
and shaded study sections during the fall of 1972, 1973,
and 1974.
69
Analysis of variance of daily instantaneous growth rates
for tagged and untagged trout of the 1971 and 1971+
year classes.
71
Analysis of variance of daily ins tanLaneous growth rates
for all trout except the 1973 year class from the unshaded and shaded study sections.
71
Page
Appendix
M
Estimated production and calcul.ations for the unshaded
and shaded study sections from April 1973 to April
1974.
N
72
Percentage composition of the diet by year class
during 1973.
74
A POPULATION STUDY OF THE CUTTHROAT TROUT IN
AN UNSHADED AND SHADED SECTION OF STREAM
INTRODUCTION
The coastal cutthroat trout (Salmo clarki clarki) inhabits many
streams draining small watersheds of western United States and
Canada. Removal of the forest canopy from some of these watersheds
has been shown to affect the physical characteristics of the stream
habitat. Numerous studies have documented changes in water temper-
ature, sedimentation, dissolved oxygen, and stream flow (Gibbons
and Salo, 1973).
Few studies have dealt with the effect of increased
light intensity on the trout population. Light energy is fixed by algae
and terrestrial vegetation bordering the stream. Algae and terres-
trial detritus in the stream are consumed by aquatic insects, which
in turn are food for trout. Removal of large shade trees from a
section of an experimental stream resulted in three times as much
light at the water surface and three-fifths as much detritus of terrestrial origin as compared to a shaded section (Warren et j. , 1964).
Increased light for laboratory streams has been shown by Brockson
et al. (1 968) to increase production of cutthroat trout.
The objective of this study was to test the hypothesis that no
differences existed in the trout populations in an unshaded and shaded
section of Mack Creek, a small stream located in the Cascade
Mountains of Oregon.
Population size, growth rate, and production
were estimated in each area, Data were also collected on movement
and diet of the trout. This study was conducted within the H. J.
Andrews Experimental Forest and is one segment of interrelated
stream research by the Coniferous Forest Biome of the International
Biological Program.
Concurrent studies on primary production,
decomposition of terrestrial detritus, feeding of aquatic insects, and
abundance of aquatic insects were also part of the research designed
to determine the sources and fates of organic material for this stream
(Sedell .!
1. ,
1974).
Some previous work with the cutthroat trout has been completed
in the H. J. Andrews Experimental Forest. Wustenberg (1954) con
ducted a preliminary survey of the influence of clearcut logging on
several small streams. He documented alterations to the physical
habitat as well as declines in aquatic insect and trout populations.
Four years later, Wyatt (1 959) again found reduced trout populations
in several of these streams. The major work by Wyatt was on life
cycle of the trout, movement, and the role of tributaries as brood
streams.
Several other population studies have been conducted on cut-
throat trout in Oregon.
Lowry (1 966) estimated annual production in
three forested streams located near the coast. For these streams
work was also completed on diet (Lowry, 1 966) and movement
3
(Lowry, 1965).
Nickelson (1974) calculated annual production for
citthroat trout in a small experimental stream in the foothills of
the Willamette Valley.
The Study Area
Mack Creek, located approximately 80 km east of Eugene,
Oregon, begins at the 1400 m level on the west slope of the Cascades
and drains an area of 8. 3 km2.
The stream runs north for 4. 4 km
into Lookout Creek, a tributary of the McKenzie River (Figure 1).
The plant community is dominated by old-growth Douglas-fir
(Pseudotsuga menziesii) and western Hemlock
(Tsug,
heterophylla).
Annual precipitation of approximately 230 cm consists of rain and
snow falling primarily during the months of October through April.
Snow normally accumulates in the watershed during winter and
remains at higher elevations until May or June.
A study site was selected to include a section of shaded watershed and a downstream unshaded area.
The unshaded section was
the result of clearcut logging. Cutting had taken place in 1965, when
3. 5 ha of timber were removed by high-lead cable logging. Little
vegetation remained along the stream and approximately 350 m of
channel were exposed. After yarding, the stream was cleared of
large debris and the area was burned. At the beginning of the study,
8 yr after logging, some vegetation had returned to the slopes and
Lookout Creek
0.Skmi
Stream ,Watershed boundary
-.-
Clearcut boundary - - Road
F
/
I-
/
I
/
-
L1
-4
100 m
Study sectiOn -ijif
Tagging site L
Thermograph 0
Falls
Mack
(_ _\
/
/
\
\
/
- _\_
/
Figure 1. Maps of the study area and location within the state of OTegon,
5
there was no apparent abnormal siltation of the stream. No appreciable shading of the stream surface had developed in the area that had
been cut. Some additional lagging has occurred within the Mack
Creek watershed, although it did not affect the study area (Figure 1).
The cutthroat trout is the only fish present in Mack Creek.
Other vertebrates include the Pacific giant salamander (Dicamptodon
ensatus) and the tailed frog (Ascaphus truei). On many occasions an
avian predator, the dipper (Cinclus mexicanus), was observed feeding
in the stream.
MATERIALS AND METHODS
Characteristics of the Study Sections
Two 200..m lengths of
one unshaded and one shaded,
served as study sections. Each contained two large pools; the remainder was riffles, cascades, and small pools. The upper boundary
of the unshaded section was approximately 240 m downstream from the
lower boundary of the shaded section (Figure 1).
Physical characteristics of the study sections were measured
during September 1973, a period of low stream flow. Stream width,
width of the water surface (excluding emergent boulders and large
debris), and depth at 20-cm intervals were recorded along 30 transects
for each section. Pools, subjectively classified as having smooth
water surface, reduced velocity, and increased depth, were identified
and their surface area calculated. Stream temperature was recorded
from May through October 1973 with thermographs located near the
low-:r ends of the study sections (Figure 1). Monthly estimates of
streamfiow were obtained from June through October 1973 by the
Embody equation (Lagler, 1956).
Population Estimation and Tagging
Population estimates were made in both the unshaded and shaded
sections at approximately 2-mo intervals from March through
October 1973. A final estimate was obtained during October 1974.
Both removal and mark-and-recapture methods were used since
neither was satisfactory for all sample dates. Fish were captured
with a Type V fish shocker manufactured by Smith-Root Inc.,
Vancouver, Washington.
Trout were tagged at seven locations (Figure 1) to determine
movement and growth. Numbered pennant tags (Pyle, 1965) measuring
2. 4 by 4. 8 mm were affixed to nearly all trout greater than 75 mm
fork length captured early in the study (Appendix A). Of the 849 trout
tagged, 468 were in the unshaded and 352 in the shaded habitats. In
addition, 29 trout were tagged below a falls near the confluence with
Lookout Creek.
The two-catch design was employed for the removal estimates
and 95% confidence intervals calculated according to equations presented by Seber and Le Cren (1967). A second method for calculating
confidence intervals, designed for small samples (Seber and Whale,
1970), was attempted, but abandoned since negative values for the
variance of the estimates and for the upper limit of the intervals occa-
sonally resulted,
For the mark-and-recapture estimates, tagged trout that were
observed during one sampling period and recaptured during the next
were considered to be recaptures for the Bailey modification of the
Peterson population estimation equation (Ricker, 1958, p. 84):
E]
M(C+l)
R+l
where
N
estimate ofpopulation size at time of marking,
M
number of marked fish,
C
number of fish examined for marks, and
R
number of recaptured marks.
Ninety-five percent confidence intervals were calculated from Ricker
(1958, p. 84),
All assumptions necessary for mark-and-recapture
estimates as discussed by Ricker (1958, p. 86) were not met. Corrections were made to account for failure to meet these assumptions
(Appendix B).
Length frequency analysis allowed reasonable separation into
age groups (Appendix C) and permitted estimates of population size for
each year class. When the grouping interval was varied from 1 to 5
mm and when a time series of distributions was viewed as a unit,
divisions between year classes could be identified. For the shaded
section, division between the 1971 and 1972 year classes was obscured
during October 1973.
When the combined distributions were analyzed
with probability paper (Harding, 1949), a bimodal curve resulted with
the division located in the expected region. A similar division was
assumed between the 1972 and 1973 year classes for the shaded
section during October 1 974.
Since small trout are difficult to capture with electrofishing
gear (Fleener, 1951), an estimate of the number of fry emerging in
each study section was made by direct enumeration. Fry in Mack
Creek initially inhabit shallow backwater areas and are relatively
easy to observe. During the last week of July 1973, approximately
2 wk following the onset of fry emergence, two observers carefully
crawled along either bank and counted visible fry. All fry were not
seen during this count. Some were observed darting from hiding
locations under rocks and debris; occasionally fry were seen in the
fast water, indicating that some fry had already moved from the back-
water areas. These observations suggested that about half the fish
in these shallow areas were visible at any one time, and the fry
counts were doubled for a crude estimate of year class size. Although
less accurate than estimates obtained with the fish shocker, this
method seemed justifiable since no other data were available.
Mortality, Growth, and Production
Mortality was expressed as an instantaneous rate with the equation given by Ricker (1958, p. 24):
to
N IN
=
elt
where
Nt
number at end of interval,
10
N0
i
number at beginning of interval,
annual instantaneous mortality rate, and
t = time interval (1 for annual rate).
The instantaneous rate is the ratio of the number of deaths during an
interval to the average population size. In addition, annual mortality
rate, a, was calculated as the fraction of the trout present at the
beginning of the year that died during the year.
Field measurements of trout length were more easily obtained
than measurements of weight, so length data were customarily coilected and converted to weight with the length-wéight relationship
(Ricker, 1958, p. 191):
iog10W = log10 a + b (Iog10L)
where
W = weight in grams,
L = length in millimeters, and
a and b = constants to be estimated.
This relationship is influenced by many factors, including habitat
and season of year (Tesch, 1968). Length and weight measurements
were made during July and October1973 in the unshaded and shaded
study sections and during April 1 973 near Tagging Site 1, an unshaded
site.
11
Growth was calculated as an instantaneous rate with the model
presented by Ricker (1958, P. 31):
w Lw
t
0
where
W = weight at end of interval,
W = weight at beginning of interval,
g=
daily instantaneous growth rate, and
t = days during interval.
Since Osborn (1 968) found that rainbow trout (Salmo gairdneri) tagged
with small pennant tags had a substantially lower rate of growth than
untagged trout, growth rate was calculated for both tagged and untagged trout from Mack Creek.
Production was estimated by the numerical model (Chapman,
1968, p. 183):
P=gB
where
P = production,
g
instantaneous growth rate, and
B = mean of initial and final biomass.
Data required were obtained from lines or curves smoothed to
estimates of the parameters.
12
Stomach Content Sampling
A biweekly program of stomach content sampling was initiated
in May and continued through October 1973. Single samples were
obtained in March and April. On each date, 15 trout were sampled
in both the unshaded and shaded habitats. Locations of capture were
approximately 50 m downstream from the lower ends of the study
sections. Although initial samples were collected during mid-morning,
sampling was changed to afternoon since a greater volume of material
was collected at this time. Trout were captured with the fish shocker,
anesthesized, and stomach contents flushed by water pumped into the
gut through a syringe inserted down the esophagus.
Stomach contents were preserved in 95% ethanol and returned
to the laboratory for analysis. Each sample was pooled by year class
of trout and the wet-weight percentage composition of the diet calculated.
Larvae and pupae of aquatic insects were sorted to genus or
family level. Adult aquatic insects, terrestrial insects, and other
prey were identified to order or other appropriate taxa. To show
broad relationships, prey groups were classified as aquatic or
terrestrial. In addition, the aquatic groups, excluding the adult
aquatic insects, were combined according to their main feeding activity (personal communication, N. H. Anderson, Dept. of Entomology,
Oregon State University, Corvallis, Oregon). The feeding or functional
13
groups (Cummins, 1974) were: 1) grazers, which feed on pen-
phyton, 2) shredders, which consume large particulate detritus,
3) collectors, which ingest fine organic particles, and 4) predators,
which prey on living insects.
For three sampling dates, mean length
of prey was calculated for a size range of trout.
Because of small size, young-of-the-year trout were not inciuded in the routine stomach sampling program. Following emergence,
seven or eight fry were captured biweekly and preserved for analysis.
Fry were collected from a location 75 to 1 25 m downstream from the
lower end of the unshaded study section.
Experiments determined that flushing of stomach contents was
effective and caused no apparent internal damage to trout.
Twenty
trout were captured near Tagging Site 1, and subjected to stomach
flushing.
The trout were preserved and later examined for remaining
stomach contents. With one exception, 90 to 100% of intact prey items
were flushed (Appendix D).
For the largest trout, only 52% of prey
greater than 4 mm total length were flushed. During the stomach
sampling program, large trout were both flushed and sampled with
alligator-eared forceps (Wales, 1962) to remove large prey. In a
second experiment, 20 trout were captured in Lookout Creek and
divided into two groups. Stomach contents of one group were flushed
by the syringe method; the second served as a control. All trout were
transported to a laboratory aquarium, fed, and observed for 30 days.
14
During this period, one trout died from the experimental group and
two mortalities occurred from the control group.
Prey Selection
Laboratory experiments on prey-size selection were suggested
after analysis of prey and predator size relationships for trout from
the natural stream. Three recirculating streams, each measuring
0. 3 by 4. 3 m and similar to the experimental streams described by
Warren and Davis (1971), were used for these experiments. Water
was exchanged at approximately 1.5 1/mm and circulated by paddle
wheel at 0. 1 rn/sec.
Trout of a similar size, previously captured
from Mack Creek, were stocked in each stream. Small trout measured 75 to 80mm, medium 120 to 125 mm, and large 170 to 195mm
fork length. All trout were held a minimum of 10 days and fed meal-
worm larvae (Tenebrio sp. ) before initiation of experiments. The
streams, provided by the Entomology Department of Oregon State
University, were located at Oak Creek Laboratory near Corvallis,
Oregon.
Each stream was enclosed in black plastic sheeting and equipped
with a one -way window that aLlowed observation of undisturbed trout.
The window was positioned at an appropriate angle to avoid the possi-
bility of a trout reacting to its own reflected image. Streams were
divided into experimental and holding sections which permitted
15
experiments to be run with individual trout. Prey were flushed from
behind the plastic blind down a tube into the experimental section.
Unconsumed prey were caught in a fine mesh straining bag.
Trout were simultaneously presented with three sizes of drifting
mealworm larvae, and the order of selection observed. Each experiment consisted of a variable number of trials depending upon the
volume of prey consumed. Approximate diameter and length of
small-sized prey were 0. 9 and 3. 0 mm, medium 1. 6 and 7. 0 mm,
and large 3. 1 and 1 5. 0 mm.
Rate of feeding by rainbow trout and reactive distance to novel
prey were shown to increase with experience (Ware, 1971).
In the
recirculating streams at Oak Creek Laboratory, cutthroat trout
were provided experience with two sizes of experimental prey. For
one experiment trout had experience with prey intermediate in size
to medium and large-sized experimental prey. For the other experiment, trout were pr'ovided additional experience with small-sized
prey. Experience consisted of routine feeding and was considered
sufficient when five consecutive prey were captured.
The data were divided into categories of unfed to half satiated,
and half to fully satiated to account for possible effects of levels of
hunger on prey selection. Whenever possible, an experiment was
replicated with two trout of each size group. Feeding sessions were
terminated when the trout failed to capture at least two consecutive
16
prey.
A preliminary experiment determined that gut evacuation by
cutthroat trout required approximately 48 hr at a mean daily water
temperature of 14.0 to 15. 4°C (Appendix E).
These trout were
fed known volumes of mealworm larvae and remaining contents
flushed from the stomach at increasing intervals of time. Trout used
in the prey-size selection experiments, conducted at similar or higher
water temperatures, were deprived food for 48 to 72 hr.
17
RESULTS
Characteristics of the Study Sections
The unshaded and shaded study sections are generally similar
in measured physical characteristics (Table 1). A slightly greater
mean depth in the unshaded section and a greater mean stream width
in the shaded section indicates more emergent rocks and large debris
in the shaded area. Although the number of poois is somewhat greater
in the unshaded habitat, the pool area and the ratio of pool area to the
area of riffles and cascades is greater in the shaded habitat.
Table 1. Physical characteristics of the unshaded and shaded study sections during September 1973.
Study section
Characteristics
Length m)
Unshaded
204
Shaded
203
Mean width of water surface (ni)
2. 82
2. 83
Mean width including emergent
rocks and debris (m)
4. 87
5. 37
575
575
Number of pools
33
30
Area of pools(m2)
89
148
Surface area of water (m2)
Pool to rifflea ratio
Mean depth (cm)
Gradient(%)
b
0. 183:1
0. 347:1
10.3
10
10
of cascades included with riffles.
bData provided by H. A. Froelich, School of Forestry, Oregon State University, Corvallis, Oregon
Small differences in water temperatures were found between
study sections. Weekly mean temperatures in the unshaded habitat
ranged from 0. 1 to 1. 0°C higher than those recorded in the shaded
habitat (Appendix F).
Highest weekly mean temperature was 14. 4°C
in the unshaded area during the first week of August. Diet fluctua-
tions were greater in the unshaded section, averaging 2. 1°C from
May through October. A mean fluctuation of 0. 6°C,was recorded
in the upstream shaded section.
The greatest fluctuation, 5. 5°C,
was recorded 9 August in the unshaded habitat; the highest tempera-
ture, 17. 0°C, was recorded in the same area for 1 hr during the
afternoon of 29 July. In the shaded habitat, diel fluctuation was
0. 5°C on 9 August, and highest temperature on 29 July was 14. 0°C.
Stream flow from June through October ranged from 0. 05 to
0. 45
m3/sec, and was variable reflecting recent precipitation. Low-
est flows were measured during August, September, and October.
Based on flow records for Lookout Creek and the area of the Mack
Creek and Lookout Creek watersheds, maximum flow in Mack Creek
.
was estimated to be 8 to 11 m3/sec during
the winter of 1973-74.
In the 8 yr since removal of the forest canopy, the disturbed
area was revegetated with species generally different than those in
the shaded habitat.
Species on the sidehills of the unshaded section
are primarily vine maple (Acer circinatum), fire-weed (Epilobium
augustifolium), and wild blackberry (Rubus ursinus); the streams ide
19
vegetation is willow (Salix sp.), sweet colt's-foot (Postasites frigidus),
and fire-weed. In the shaded habitat, the canopy is predominantly
Douglas-fir, western hemlock, and western red cedar (Thuja plicata);
the understory is vine maple, huckleberry (Vaccinium sp. ), and
devil's club (Oplopanax horridum). Streamside vegetation is dom-
mated by vine maple, devil's club, and sweet colt's-foot.
Population Size
The unshaded section supported a higher number of trout than
the shaded section (Figure 2).
For the 1973 through 1971 year classes,
approximately twice the number of trout were estimated in the unshaded area. From April to October 1973, the 1970+ year classes
were somewhat more abundant in the shaded area. From October 1 973
to October 1974, the 1971+ year classes were estimated to be more
numerous in the unshaded section (Figure 2).
Population estimates calculated by the removal method in-
creased from April through October 1973 for all trout except those
in the 1970+ year classes (Figure 2 and Appendix G). This increase
cannot be satisfactorily explained by immigration since no suitable
tributaries exist. Also, tag recapture data indicate little movement
occurred in Mack Creek. A hypothesis proposed to explain the
ascending survivorship curves suggests that all trout captured during
later estimates were actually within the study sections during earlier
20
400
300
50
20
10
1
0
0
I
April
1973
Figure 2.
June
Aug.
Oct.
Dec.
Feb.
1974
April
June
Aug.
Oct.
Population size and survivorship by year class from April 1973 to October 1974.
Open symbols represent estimates for the unshaded and closed symbols for the shaded
study sections. Bars indicate 95% confidence intewals. Solid lines were drawn
through best estimates of population size. See Table 2 for methods used for best
estimates. Dashed lines connect estimates by the removal method.
21
0
0
Co
50
I
20
April June
1973
Aug.
Oct.
Dec.
Feb.
April
1974
Figure 2. (Continued)
June
Aug.
Oct.
22
estimates, but were unavailable for capture. A portion of the population, because of a behavioral response when frightened, was probably
nosed into crevices among the abundant large boulders.
Survivorship curves drawn to the mark-and-recapture estimates
are descending (Figure 2). These curves were assumed to be more
realistic estimates of population size than those provided by the
removal method. Recaptures were not obtained following the October
1 973 and October 1 974 sampling, and removal estimates were used
for these dates
During April in the unshaded and April and June in the shaded
section, trout of the 1972 year class were less than the minimum
length for tagging.
Therefore, mark-and-recapture estimates were
not possible for April 1973 in the unshaded and April, June, and
August 1973 in the shaded section. Survivorship curves were extrapolated back in time from the June estimate for the unshaded and the
October estimate for the shaded section assuming the same rate of
mortality as existed after June for the unshaded and October for the
shaded section. Estimates for the 1971+ year classes in October 1973
were calculated by summing the 1971 and 1970+ estimates at that time.
Methods providing best estimates of population size are shown in
Table 2.
Biomass of trout in the unshaded section was greater than biomass in the shaded section. During October 1973, the estimate in the
23
unshaded habitat was 1 2. 2 g/m2, nearly twice that of the shaded
habitat (Table 3).
Biomass decreased in both habitats by October
In the unshaded area, the estimate was 10. 1 g/m2, approxi-
1974.
mately 2. 5 times the estimate from the shaded area (Table 3). Bio-
mass estimates and area measurements were calculated during periods of low stream flow.
Table 2. Methods used for best estimates of population size from April 1973 to October 1974.
Year
class
Study
section
Unshaded
Shaded
1973
1972
1971
1970+
1971+
1973
1972
1971
1970+
1971+
1974
1973
April
August
June
Visuala
M and R
M and R
M and R
Extrapolation
M and R
M and R
M and R
M and R
M and R
Visuala
Extrapolation
M and R
M and R
Extrapolation
M and R
M and R
Extrapolation
M and R
M and R
October
October
Removal
Removal
Removal
Removalb
Removal
Removal
Removal
Removal
Removal
Removal
Removal
Removal
Removalb
Removal
aEstimates made in last week in July.
bCalculated by summing the 1971 and 1970+ estimates
Table 3. Estimated biomass g/m2) in the unshaded and shaded study sectionsduring October 1973
and October 1974.
Year class
Study
Total
Year
1974
1970+
1971+
section
1973
1971
1972
12.2
1973
4.6
Unshaded
0.7
4.5
2.4
14
6.2
0.3
3.6
Shaded
0.9
1974
Unshaded
Shaded
0.2
0.2
2.8
0.5
2.7
0.9
4.4
2.2
10.1
3.8
Separate weight-prediction equations were used for trout from
the unshaded and shaded areas (Appendix H and I).
Within each area,
seasonal variation also required the use of separate equations. No
24
weights were available for 1974, so the 1973 weight-prediction equations were used for 1 974 calculations.
Mortality, Growth, and Production
Mortality rates were similar between study sections for all but
the 1973 year class. Mortality was highest for the oldest trout.
Generally, annual mortality was greater than 50% (Table 4).
Table 4. Annual instantaneous mortality (i) and annual mortality (a) rates by year class from
October 1973 to October 1974.
Study
section
Year
class
I
a
Unshaded
1973
1972
1971+
0.31
0.84
1.15
0.27
0.57
0.68
Shaded
1973
1972
1971+
0.83
0.78
0.56
0.55
0.68
1.13
Mean length by year class was greater for trout residing in the
unshaded than in the shaded section (Figure 3).
The difference was
apparent for the 1973 year class by early August, less than 1 mo after
emergence, and generally increased witb. trout age for the first three
years of life. For three consecutive years, 1972 through 1974, mean
lengths of the year classes during the fall were greater for trout captured in the unshaded than in the shaded habitat (Appendix J).
Growth was greatest from April through October (Figure 3).
160
VVTV
_.___-i
---
--
0- ----.-------
120
iibC
-,
- - 0
-I
-
-
80
Yearclasses
1973
1972
L
1971
0
1970+
1971+
April
1973
Figure 3.
June
Aug.
Oct.
Dec.
April
I
June
Aug.
0
I
I
Oct.
Dec.
1974
Growth curves by year class from April 1973 to October 1974. Open symbols represent estimated mean lengths for trout in the
unshaded and closed symbols the shaded study sections. Estimates for the 1971+ year classes in October 1973 were obtained by
combining the 1971 and 1970+ data at that time.
Li'
2b
Trout tagged in October and November 1972 and recaptured in March
and April 1973 showed some growth during winter,
In the unshaded section, mean length of fry captured during
October was variable from year to year (Appendix J). During 1973
and 1974, mean length of fry in this section was 56 and 51 mm, respectively.
For both years, mean length of fry in the shaded section was
approximately 48 mm.
During 1973, fry in the unshaded habitat emerged somewhat
earlier than fry in the shaded habitat. Qn 10 July, several fry were
observed in most backwater areas in the unshaded section, but only
three fry could be found in the shaded section.
No consistent differences were apparent between daily instantaneous growth rates of tagged and untagged trout (Table 5). The data
conform to the design of a 2 x 2 x 3 factorial experiment. Analysis
of variance showed growth rates of tagged and untagged trout, and
trout from the unshaded and shaded study sections were not significantly different (Appendix K).
Data for tagged and untagged trout were pooled (Table 6), and
analysis of variance of a second factorial design again showed no
differences in growth rates of trout from the unshaded and shaded
study sections (Appendix L).
This analysis included data for all trout
captured during the population estimates except the 1973 year class.
Annual production was estimated to be 7. 5 g/m2 in the unshaded
27
Table 5. Daily instantaneous growth rates of tagged and untagged trout during 1973. The 1972 and
1973 year classes are not included since these trout were too small to tag.
section
Year
class
Interval for
calculation
Unshaded
1971
April to June
June to Aug.
Aug. to Oct.
April toJune
June toAug.
Aug. to Oct.
Study
1970+
Shaded
1971
1970+
Tagged
0. 0036
0. 0024
0.0032
-0. 0008
0.0015
0.0015
-0. 0008
-0.0003
0.0003
0.0009
April to June
June to Aug.
0.0038
Aug. to Oct.
April to June
-0.0014
June to Aug.
0. 0008
-0. 0012
Aug. to Oct.
Growth rate
Untagged
0. 0033
0.0007
0.0031
0.0001
0. 0049
0. 0012
-0. 0026
-0. 0003
0.0007
-0. 0003
Table 6. Daily instantaneous growth rates of trout in the unshaded and shaded study sections during
1973. Data for tagged and untagged trout have been combined.
Growth rate
Shaded
Year
class
Interval for
calculation
Unshaded
1973
Aug. to Oct.
0.0134
0.0140
1972
April to June
June to Aug.
0.0048
0.0089
0.0010
0.0075
0.0093
0.0006
0.0033
0.0047
0.0023
-0.0015
Aug. to Oct.
1971
1970+
April to June
June to Aug.
Aug. to Oct.
-0. 0007
ApriltoJune
0.0011
June to Aug.
0. 0010
0. 0005
Aug. to Oct.
0. 0025
0.0013
-0. 0007
-0.0008
and 2. 6 g/m2 in the shaded section (Appendix M).
Percentage contri-
bution to total annual production by the 1973 and 1972 year classes
was similar in both habitats (Table 7). Production was greatest for
the 1971 year class. The 1970+ year classes contributed an estimated
19% of the total production in the unshaded and 8% in the shaded section.
Production of the youngest trout, the 1 973 year class, was
approximately 1 5% of the total in both areas.
This percentage is lower
than expected because the interval, used for computation resulted in
an approximate 8-mo contribution for this year class.
Production was seasonal, high in the spring and early summer
and low in the late summer, fall, and winter. Approximately 65%
of the production occurred in both habitats during the 4-mo period
from April through July (Table 7). Loss of weight by trout that
survived the interval, termed negative production, occurred for
some older year classes primarily between August and October.
Movement
Most tagged trout were recaptured near the site of previous
observation. Of 871 trout recaptured between March and November
1973, 96% in the unshaded and 92% in the shaded habitat were recovered within 25 m of the location where Last observed. Only 1% had
moved more than 100 m (Table 8). Since data were collected during
population estimates and stomach content sampling and both activities
29
Table 7. Estimated production by year class in the unshaded ax shaded study sections from April
1973 to April 1974. Daily rates are included below entry for the interval.
Production g)
(
section
Year
class
Unshaded
1973
Study
1972
1971
1970+
Total(%)
Shaded
April-
June-
Aug. -
June
Aug.
Oct.
4a
1.8
623
82
341
5.0
11.3
1.4
1.8
783
433
-115
11.5
79
-2.0
340
189
89
5.0
3.4
1.5
1463(34)
21.5
1245(29)
22,6
400(9)
6.9
44a
2.6
1971
1970+
Total(%)d
346b
194b
1216(28)
1447 (33)
812(19)
4324
78
222 (15)
0.4
16
107
4.2
0.3
0.6
297
130
-74
4.3
2.2
-1.3
288
-108
-109
4.2
-1.9
-2.0
0.3
- 23
-0.4
2.8
4.5
1386 (32)
6.6
241
263(18)
679 (16)
1.1
2.3
740 (49)
Total
i.9
155
10.7
a
335
5.9
340
1973
1972
Oct. April
519 (35)
621 (42)
1.5
54c
507 (33)
125( 8)
1487
Computed from last week of July
bTotal production of 540 g for the 197 1+ year class was proportioned on the basis of production by the
1971 and 1970+ year classes from April to October 1973.
CTotal production of 322 g for the 1971+ year class was proportioned on the basis of production by
the 1971 and 1970+ year classes from April to October 1973.
d
Approximate percentage since negative production was estimated for the August to October intervaL
30
were repeated in approximately the same locations, a bias was introduced in favor of observations of trout remaining near the site of
previous capture.
Table 8. Movement of trout from March to November 1973. Data were organized on basis of
bimonthly interval of previous observation. Days between observations were chosen so
each would contain data from only one succeeding population estimate.
interval of
March-April
>100
25
26-100
>100
58
5
0
56
8
18
0
1
15
2
1
)60
4
0
0
0
2
0
5(6)
1(1)
80(93)
71(84)
12(14)
1
2(2)
80
127
5
0
183
15
81-160
20
2
0
34
1
>160
0
0
0
147(95)
7(5)
0(0)
217(92)
122
2
0
166
8
0
6
0
0
6
0
0
0
0
0
0
0
0
0(0)
172(96)
8(4)
0(0)
1(<1)
460(92)
36(7)
5(1)
Subtotal(%)
July-Aug.
25
26-100
desiaçd distancesjj._.....
Shaded
Unshaded
81-160
Subtotal(%)
May-June
Numbers of trout moving
Days
previous between
observation observations
80
81-160
>160
Subtotal(%)
128(98)
2(2)
Total(%)
355(96)
14(4)
0
0
16(7)
3
0
0
3(1)
To obtain unbiased estimates of trout movement and information
on movement over extended periods of time, approximately 975 m of
stream were sampled during July and August 1974.
The section ex-
tended from 300 m below the lower end of the unshaded section up-
stream to the upper falls (Figure 1). Movement was caIculated from
31
the date of tagging.
The 60 recaptured trout were divided into two
groups, those tagged for one and two winters. For each group,
approximately 70% were recaptured within 25 m of the tagging site.
Of all trout recaptured, only 1 0% had moved more than 1 00 m (Table 9).
Table 9. Movement of trout tagged for one or two winters before recapture during July and August
1974.
Winters
before
Numbers
recapture
1
Habitat
Unshaded
Shaded
Subtotal
2
(
%)
<5
12(60)
19(83)
31(72)
of trout moving designated distances (m)
> 100
26-100
9(21)
1( 5)
2( 9)
3( 7)
7(35)
2( 9)
0
2 (50)
2(15)
2(12)
1 ( 8)
Subtotal
10(77)
12(70)
Total
43(72)
11(18)
6(10)
Unshaded
Shaded
2 (50)
3(18)
Two major barriers, the falls near the confluence with Lookout
Creek and a culvert at a road crossing located between the study sec-
tions (Figure 1), apparently prevented upstream movement. No trout
tagged below these barriers were recaptured above them. One trout
of 353 tagged within the shaded habitat, moved downstream through
the culvert and was recaptured approximately 670 m downstream.
32
Diet
The trout diet was diverse and typically represented by several
groups of Ephemeroptera, Plecoptera, Trichoptera, and Diptera
(Appendix N).
Non-insect aquatic groups and terrestrial insects were
normally present in the stomach samples. Epeorus and Baetis
formed a large percentage of the diet in both the unshaded and shaded
habitats during the spring and early summer. Leuctridae were cornmon in the guts from the shaded area during March and April and in
both habitats during May and late September.
Throughout the sarup-
ling period, Chironomidae consistently contributed large numbers of
individuals, but because of their small size the contribution by weight
was normally less than 5%.
Trout rarely took vertebrates. Of the
420 stomach contents examined, only one contained remains of another
cutthroat trout and five contained remains of larvae of the tailed frog.
Diet of fry, the 1973 year class, was similar to that of larger
trout (Appendix N). Ephemeroptera, prtncipally represented by
Baetis, was an important component throughout the sampling period.
Leuctridae were abundant during late September as they were for
larger trout. Chironomidae composed a greater percentage of the
diet than was found for the older year classes. Several of the largest
prey, adult Tipulidae and vertebrates, were not found in stomach
contents of fry.
33
A similar percentage of the trout diet from the unshaded and
shaded habitats was terrestrial (Figure 4, Part A). Although terrestrial groups were relatively unimportant in the diet during spring,
contribution of terrestrials increased during summer and peaked in
August at nearly 70% of the diet in both habitats. Older trout captured
a greater percentage of terrestrial prey than younger trout (Figure 4,
Part B and C).
Of the functional groups, grazers were more abundant in the
diet from the unshaded habitat from April through June than from the
shaded habitat (Figure 5). No pattern could be detected in the abun-.
dance of the shredder, collector, and predator groups between study
areas.
From March through October, larvae and pupae of Chironomidae
and larvae of Baetis comprised 1 5% of stomach contents of trout captured in the unshaded and 9% in the shaded area. Only during April
was the contribution in the unshaded less than in the shaded habitat
(Figure 6). These insects with a short life cycle and more than one
generation per year (Waters, 1961; personal communication, N. H.
Anderson, Dept. of Entomology, Oregon State University) could
provide a more productive food resource for trout than insects requiring one or more years to mature.
No consistent relationship was found between mean prey length
and trout length for three sampling dates from March through
34
O0
60
20
100
5)
60
;
C
C
0
.0
E
C
20
0
U
100
60
20
April
June
Aug.
Oct.
Figure 4. Terrestrial component by weight of the trout diet during 1973. Year classes
are combined (Part A) and presented separately for the unsh3ded (Part B) and
shaded (Part C) study areas. Open symbols represent the unshaded and closed
Vertebrates in the diet are excluded from
symbols the shaded habitats.
the totals. Data are combined by monthly intervaL
10
40
20
.
60
0
4-.
0o
40
20
April
June
Aug.
Oct.
April
June
Aug.
Oct.
Figure 5. Functional group components by weight of the trout diet during 1973. Vertebrates in the diet are exckided in this
analysis. Data are combined by monthly interval.
(J
u-I
40
4J
20
0
U
April
Figure 6.
June
Aug.
Oct.
Combined contribution by weight of immature stages of Chironomidae and Baetis in the trout diet during 1973. Vertebrates
in the diet are excluded from the totals. Data are combined by monthly interval.
37
October 1973 (Figure 7). The only exception was the July sample
collected in the unshaded habitat. SmaIltrout did not consume the
largest prey, but all trout consumed small prey. Large prey cornposed only a small percentage of the nuraber of prey consumed by
medium and large-sized trout. Prey consumed in the unshaded and
shaded habitats were similar in size.
Prey Selection
In laboratory experiments, as in stomach content samples of
trout from the natural stream, no consistent relationship existed
between trout size and size of the selected prey (Figure 8). When
trout were simultaneously presented with three sizes of drifting
mealworm larvae, the largest prey were normally selected. Small
trout with empty guts were somewhat less selective and more likely to
capture medium-sized prey. As feeding trials progressed and trout
approached satiation, the consistency of selection of large prey
increased,
Additional experience with small-sized prey made no apparent
difference in the pattern of prey selection (Figure 8). In the majority
of trials, trout continued to select the largest prey.
16
22 March
Unshaded
12
0
Shaded
8-
1
-
iTi
I!
urn
4
;iji
'9
] +-4
J_
-a-
20 July
12
883 + .016 (x
754
-r
bt
C
+
5)
Ii-
T
280ct.
-r
IT
8
oT
11r
T
IJ'
'1
1i
lIT
eel
LII,oll::I
I
I
30
60
90
I
120
I
150
180
Trout length (mm)
Figure 7. Mean prey length and trout length for three dates during 1973. Bars
represent range of prey length. Significant regression ( p <.05) occurred
only for the 20 July sample from the unshaded habitat.
Experiment A
Unfed to 50% satiated
Experiment B
Unfed to 50% satiated
n=9
n
8
100
Prey size
60
Small
D
Medium
20
Large
50 to 100% satiated
0
0
100
n5
n12
n28
50 to 100% satiated
n2
n12
Small
Medium
(I,
60
20
Small
Medium
Trout size
Large
Large
Trout size
Figure 8. Selection of three sizes of prey by trout during laboratory experiments. Trout in Experiment A had experience with prey intermediate
in size to the medium and large-sized experimental prey. In Experiment B, trout were provided additional experience with small-sized
prey. Lined bars show results for separate fish whenever two trout of each size were tested. Number of trials is indicated above each
set of bars.
(J-,
40
DISCUSSION
Significant differences in population levels, mean size by year
class, and production were found for cutthroat trout residing in the
unshaded and shaded study sections. Increased light intensity in the
unshaded section resulted in a greater percentage of grazing insects
in the trout diet and probably contributed to the greater trout production in this area.
Lyford and Gregory (1975) reported greater algal
biomass in the unshaded section of Mack Creek compared to the
shaded section. Some insight was obtained into other mechanisms
that may have contributed to diffexences in the trout populations
between the unshaded and shaded habitats.
Increased percentage of grazing insects in the diet of trout
from the unshaded habitat may indicate a somewhat different energy
base for this area as compared to the shaded section. Although the
data were variable, contribution of the shredder group in the trout
diet was not noticeably lower in the unshaded habitat. This may mean
that input of terrestrial detritus remained high after removal of the
forest canopy.
In the unshaded section, the mix of autochthonous and
allochthonous material may have combined to form an energy base
greater than that in the shaded habitat.
Light intensity and algal production were increased in sections
of an experimental stream studied by Warren et al. (1 964) after
41
removal of shade trees. No consistent differences in production of
cutthroat trout were apparent between unshaded and shaded sections.
In this stream a large biornass of the snail Oxytrema silicala was
present. The snail was a principal consumer of algae and terrestrial
detritus. Snails were not important in the diet of trout, so changes
in the energy sources for the study sections were not reflected in
trout production.
Few snails were present in Mack Creek, and
the trout population was more able to respond to changes in the
energy base.
Abundance of all aquatic insects combined was probably greater
in the unshaded than the shaded habitat. From June through October
1972 and from mid-February through mid-August 1973, emergence
traps in the unshaded area captured approximately four times the
biomass of adult aquatic insects as traps in the shaded area (1974
Annual Report, Edward J. Grafius and Norman H. Anderson, unpublished, Dept. of Entomology, Oregon State University).
Coche (1967)
discussed the possibility of attracting or repelling insects by emergence traps. Based on microhabitat and life history characteristics,
Ephemeroptera, Chironomidae, Rhyacophilidae, Leactridae, and
Taeniopterygidae were probably sampled in proportion to their aban-
dance in the stream (personal communication, Norman H. Anderson,
Dept. of Entomology, Oregon State University). Approximately twice
the biomass of these insects emerged in the unshaded as compared
42
with the shaded habitat. In both labitats, these groups were impor-
tant in the trout diet, composing from 22 to 81% of stomachcontents
sampled from March through June, the interval of highest contribution of aquatic insects. In nine of 1 2 samples this contribution was
greater than 50%.
The consistently greater percentage in the trout diet of multivoltine insects, Chironomidae and Baetis, probably indicates a
greater abundance of these more productive insects in the unshaded
habitat. A more productive food resource could contribute to the
higher level of trout production in this area.
Early emergence of fry in the unsladed section during July, a
month of high trout growth, may have provided a size advantage that
was maintained throughout the life of the trout. Elevated water tern-
peratures in the unshaded as compared to the shaded section are
believed responsible for the earlier emergence. Merriman (1935)
found the onset of hatching of cuttlaroat trout eggs to be linearly
dependent on temperature, increasing from 6.35 to 11. 30°C.
1
employed Merriman' s relationship and temperature records from
Mack Creek, and calculated time from feztilization to first hatching
for both study sections. This developmental period would have
required approximately four days longer in the shaded habitat.
Elevated water temperature may also have contributed to earlier
spawning in the unshaded section as well as accelerated development
43
of the alevins (Hayes and Pelluet, 1945). The possibility of early
emergence and an early start in life was discussed by Narver (1972)
as an explanation for differences in size of three year classes of a
combined cutthroat and juvenile steelhead trout population from a
logged and forested section of a stream on Vancouver Island.
Further evidence that water temperature controlled emergence
is found in the mean lengths of fry during October 1973 and October
1974.
In 1973, fry from the unshaded section averaged 8 mm longer
than from the shaded section. The following year the difference
was only 3 mm. In 1 974 a more abundant snow melt maintained a
high stream flow during spawning and while the eggs and alevins were
developing.
This probably minimized temperature differences be-
tween study sections and tended to synchronize emergence.
A potential competitor with the cutthroat trout, the Pacific giant
salamander, is present in abundance in the unshaded and shaded
study sections. In a small stream in Washington, diet of salamanders
was similar to the diet of cutthroat trout in Mack Creek, being primanly composed of Ephemeroptera, Plecoptera, and Diptera
(Antonelli et al.
,
1972).
The possibility of unequal competition
between trout and salamanders in the unshaded and shaded habitats
of Mack Creek provided stimulus for an investigation of the salamander population.
The estimated biomass, higher than the biomass of
trout, was 15. 7 g/m2 in the unshaded and 18. 8 g/m2 in the shaded
44
section (R. S. Aho and M. Marangio, unpublished data, Dept. of
Fisheries and Wildlife, Oregon State University). The difference
was considered not significant because of wide confidence intervals
for the population estimates. In addition, no differences were evi-
dent in the age structure as revealed by length frequency histograms.
Further work is necessary to more precisely determine population
levels of salamanders and to understand the nature of the interaction
between these two vertebrates.
The estimates of trout production, 7. 5 g/m2/yr in the unshaded
and 2. 6 g/m2/yr in the shaded section, are generally similar to
estimates for cutthroat trout from other streams in Oregon. Lowry
(1966) estimated production to range from 3. 5 to 4. 9 g/m2/yr for
three coastal streams. A small experimental stream in the
Willamette Valley had an estimated production of O. 5 g/m2/yr
(Nickelson, 1974).
Estimates of trout production from streams outside Oregon are
generally greater than those of Mack Creek. Production of brook
trout (Salvelinus fontinalis) in Lawrence Creek, Wisconsin was
estimated over an 11 yr period and averaged 11.7 g/m2/yr (Hunt,
1974).
In New Zealand, Allen (1951) estimated production of brown
trout (Salmo trutta) to range from 27 to 84 g/m2/yr in several sections of the Horokiwi Stream.
The mean for this stream was ap-
proximately four times higher than estimates of annual production
45
reported elsewhere for salmonids(Le Cren, 1969). Possible errors
in estimates of population size of young brown trout were discussed
by Chapman (1967)
The higher level of trout production in the unshaded section can
be attributed to an increased mean biomass in that area. Growth
rates between sections were not significantly different. Mean biomass is influenced by numbers of trout and their mean weight.
McFadden (1969) suggests that with ter-rI.torial species an abundance
of food causes a decrease in territory size and an increase in fish
density.
Increased availability of food probably accounts for the
greater number of trout in the unshaded section; earlier emergence,
as previously discussed, accounts for the larger trout size.
Biomass may have an effect upon production, and the relation-.
ship between production and biomass has often been expressed as a
ratio. In Mack Creek, the ratio of annual production to mean annual
biomass was 0. 59 for the unshaded and 0. 38 for the shaded section.
This ratio, calculated for the cutthroat trout studied by Lowry (1966),
ranged from 0. 87 to 1. 04.
Variability in the ratio of annual produc-
tion to mean annual biomass for cutthroat trout from small Oregon
streams is probably a result of factors such as fluctuations in the
availability of prey or difference in age structure of the populations.
Although no consistent relationship was found between mean
prey length and trout length, some partitioning of the food resource
46
is suggested by absence of the largest prey from stomach contents
of the smallest trout. Reduced size of prey consumed by fry has
been described for salmonids from other streams. Brown trout fry
from a Swedish river were found o consume smaller and earlier
life history stage of aquatic insects of the same genera as were consumed by larger trout (Nilsson, 1957). The importance of small
insects for survival of coho salmon fry was stressed by Mundie (1969).
Larger insects were food for larger coho srnolts. For cutthroat trout
from the Cowichan River in British Columbia, a shift in diet from
insects to larger prey, principally fish, was noted for trout greater
than 200 mm (Idyll, 1 942).
Few cutthroat trout in Mack Creek exceed
200 mm, and in apparent agreement with the data from the Cowichan
River, insects were the major prey with fish and other large vertebrates rarely consumed.
Most prey consumed by trout in Mack Creek were smaller than
prey selected during laboratory experiments. For the field studies,
mean prey length ranged from 1 to 7 mm. In the laboratory streams,
trout normally selected the largest prey offered, measuring approximately 1 5 mm.
This suggests that few large prey are available in
Mack Creek.
Descending survivorship curves drawn to the mark-and-recap-
ture population estimates tend to support the hypothesis that during
the removal estimates some trout were unavailable for capture.
47
These fish were probably lodged in cracks within the substrate.
Reaction of a fish within an electrical field is to become paralyzed
or to swim in a forward direction toward the anode (Edwards and
Higgins, 1973). Neither reaction would readily dislodge a trout
from a constrictive crevice. During snorkel diving observations,
frightened trout were seen to dart wildly and soon disappear into the
substrate. As the seasons advanced and stream flow decreased, the
number of hidinglocations was reduced. Differences between num-
bers of trout estimated by the two methods decreased from April
through August. In August, a month of low stream flow, removal
estimates were slightly lower than mark-and-recapture estimates.
This may indicate that in rocky-substrate streams, even under ideal
conditions of stream flow, the two methods will consistently provide
somewhat different results.
No data are available on the growth and abundance of cutthroat
trout in Mack Creek before removal of the forest canopy by clearcut
logging.
As a result, no definitive conclusion can be reached on the
relationship between timber harvest and the trout population. Nevertheless,, the pronounced differences between study sections warrant
some discussion of other studies eLatiag logging and trout populations.
Previous work in the H. J. Andrews Experimental Forest showed
that immediately after logging cutthroat trout were eliminated from
affected sections of three small streams (Wustenberg, 1954).
Four
years later, one of the streams had repopulated but only the lower
30 to 40 m of the other two were inhabited by trout (Wyatt, 1959).
Near the Oregon coast, a population of cutthroat trout was reduced
in Needle Branch during the 8 yr following clearcutting of the water-
shed. Mean population size was approximately a third of pre-logging
levels (Moring and Lantz, 1975). In four other coastal streams,
the number of cutthroat trout the year before logging was compared
to the number the year following logging. Decline in the trout popula-
tions for the second year ranged from 4 to 49% (Moring and
Lantz, 1974). On Vancouver Island, the number of a combined
group of cutthroat and juvenile steelhead trout from a logged section
was approximately half the number from an upstream forested section of stream (Narver, 1972). Some possibly important differences
exist between these studies, which relate declining trout populations
and logging activities, and the present study on Mack Creek. First,
with the exception of Needle Branch, the trout populations were
sampled within a period of less than 5 yr after logging. The unshaded
section on Mack Creek was 8 yr old at the beginning of this study.
Second, although the size of the disturbed areas was not included in
descriptions of all the previous studies, it is probable these sites
were larger than the logged area on Mack Creek. Other differences,
including protection of the stream during logging, aspect of the site,
and soil type may also be important. Whatever factors involved,
stream habitat in the unshaded section on Mack Creek appears to
be more suitable for cutthroat trout than the shaded area.
50
LITERATURE CITED
Allen, K. R.
The Horokiwi stream: a study of atrout population. New Zealand Marine Dept. Fish. Bull. 10. 238 pp.
1951.
Antonelli, A. L., R. A. Nussbaum, and S. D. Smith. 1972. Comparative food habits of four species of stream-dwelling vertebrates (Dicamptodon ensatus, D. copei, Cottus tenuis, Salmo
gairdneri). Northwest Sci. 46(4): 277-289.
Brockson, R. W., G. E. Davis, and C. E. Warren.
1968.
Compe-
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51-75.
Chapman, D. W. 1967, Production in fish productions. Pages 3-29
In S. D. Gerkirig (ed.) The biological basis of freshwater fish
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Production. Pages 182-196 In W. E. Ricker
(ed. ) Methods for assessment of fish production in fresh waters.
International Biological Program Handbook No. 3. Blackwell
Scientific Publications, Oxford and Edinburgh.
1968.
Coche, A. G. 1967. Production of juvenile steelhead trout in a
freshwater impoundment. Ecolog. Mono. 37(3): 201-228.
Cummins, K. W. 1974. Structure and function of stream ecosystems,
Bioscience 24(11):631 -641.
Edwards, J. L., and J. D. Higgins.
The effects of electric
currents on fish. Final technical report, Projects B-397,
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1 973,
Fleener, G. G. 1951. Life history of cutthroat trout, Salmo clarki
Richardson, in Logan River, Utah. Trans. Amer. Fish. Soc.
81:23 5-248.
Gibbons, D. R., andE. 0. Salo.
Anannotatedbibliography
of the effects of logging on fish of the western United States
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Pac. Northwest For, and Range Exp. Stn., Portland, Oregon.
145 pp.
1973.
51
Harding, 3. P. 1 949, The use of probability paper for the graphical
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Ass. U. K. 28:141-153.
Hayes, F. R.
and D. Pelluet. 1945. The effect of temperature on
the growth and efficiency of yolk conversion in the salmon
embryo. Can. 3. Res. 23(2):7- 15.
,
Hunt, R. L. 1 974. Annual production by brook trout in Lawrence
Creek during eleven successive years. Tech. Bull. 81.
Wisconsin Dept. of Nat. Res. 29 pp.
Idyll, C. 1942. Food of rainbow, cutthroat, and brown trout in the
Cowichan River system, B. C. J. Fish. Res. Bd. Can. 5:448-.
458.
Lagler, K. F.
1956.
Freshwater Fishery Biology. Wm. C. Brown
Co., Dubuque, Iowa. 421 pp.
Le Cr en, E. D. 1 969. Estimates of fish populations and production
in small streams in England. Pages 269-280 In T. G. Northcote
(ed. ) Symposium on salmon and trout in streams. H. R.
MacMillan Lectures in Fisheries. Univ. of British Columbia,
Vancouver, B. C.
Lowry, G. R. 1965, Movement of cutthroat trout, Salmo clarki
clarki (Richardson) in three Oregon coastal streams. Trans.
Amer. Fish. Soc. 94:334-338.
Production and food of cutthroat trout in three
Oregon coastal streams. J. Wildl. Mgmt. 30:754-767.
1966.
Lyford, J. H. , Jr., and S. V. Gregory. 1975. The dynamics and
structure of perphyton communities in three Cascade Mountain
streams. Verh. hit. Verein. Limnol. 19:1610-1616.
McFadden, 3. T.
1 969.
Dynamics and regulation of salmonid popula-
tions in streams. Pages 313-329 In T. G. Northcote (ed.
Symposium on salmon and trout in streams. H. R. MacMillan
Lectures in Fisheries. Univ. of British Columbia, Vancouver,
B.C.
Merriman, D. 1 935. The effect of temperature on the development
of eggs and larvae of the cutthroat trout (Salmo clarki clarki
Richardson). J. Exp. Biol. 1 2(4):297-305.
52
Moring, J. R., and R. L. Lantz.
Immediate effects of
logging on the freshwater environment of salmonids. Oregon
Wildi. Comm., Fed. Aid Rept. Project AFS-58. 101 p.
1 974.
The Alsea Watershed
Study: Effects of logging on the aquatic resources of three
headwater streams of the Alsea River, Oregon. Part I Biological Studies. Oregon Dept. Fish and Wil.dL, Fish. Res.
and ___________.
Rept. 9.
1975.
66 pp.
Mundie, J. H. 1969. Ecological implications of the diet of juvenile
coho in streams. Pages 135-152 In T. G. Northcote (ed.
Symposium on salmon and trout in streams. H. R. MacMillan
Lectures in Fisheries. Univ. of British Columbia, Vancouver,
B.C.
Narver, D. W. 1972. A survey of some possible effectsof logging
on two eastern Vancouver Islad streams. Fish. Res. Bd.
Canada. Tech. Rept. 323. 55 pp.
Nickelson, T. E. 1974. Population dynamics of coastal cutthroat
trout in an experimental stream. M. S. Thesis. Oregon State
Univ., Corvallis. 38 pp.
Y
Nilsson, N. A. 1957. On the feeding habits of trout in a stream of
northern Sweden. Rep. Inst. Freshwater Res. Drottningholm
38:1 54-1 66.
Osborn, C. E. 1968. A population study of the rainbow trout (Salmo
gairdneri) in a central Oregon stream. M. S. Thesis. Oregon
State Univ.
,
Corvallis. 65 pp.
Ostle, B. 1963. Statistics in research; basic conqepts and techniques
for research workers. 2nd ed. Iowa State Univ. Press, Ames.
585 pp.
Parker, R. A. 1955. A method for removing the effect of recruitment on Peterson-type population estimates. J. Fish. Res.
Bd. Can. 1 2(3):447 -450.
Pyle, E. A. 1965. Comparative tests of three types of vinyl tags
on growth and swimming performance of brook trout within a
hatchery. Pages 48-52 In The nutrition of a trout, Cortland,
New York. (New York. Conservation Dept. Fisheries Research
Bulletin 28. Cortland Hatchery Report No. 33 for the year 1964).
/
53
Ricker, W. E. 1958. Handbook of computations for biological statistics of fish populations. Fish. Res. Bd. Can. Bull. 119. 300 pp
Seber, 0. A. F. , and E. D. Le Cren. 1967. Estimating population
parameters from catches large relative to the population. 3.
Anim. Ecol. 36(3):631-643.
Seber, G. A. F., and J. F. Whale.
The removal method for
two and three samples. Biometrics 26(3):393-400.
Sedell,
3. R.,
1 970.
F. J. Triska, J. D. Hall, N. H. Anderson, and
3. H. Lyford. 1974. Sources and fates of organic inputs in
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R. L. Edwards (eds. ) Integrated research in the coniferous
forest biome. Bulletin No. 5. Coniferous Forest Biome.
U. S. /IBP.
Tesch, F. W. 1968. Age and growth. Pages 93-123 mW. E. Ricker
(ed. ) Methods for assessment of fish production in fresh waters.
International Biological Program Handbook No. 3. Btackwell
Scientific Publications, Oxford and Edinburgh.
Wales, 3. H. 1 962. Forceps for removal of trout stomach content.
Progr. Fish-Cult. 24(4):l71.
Ware, D. M. 1971. Predation by rainbow trout (Salmo gairdneri):
the effect of experience. 3. Fish. Res. Bd. Can. 28(12):
1847-1852.
Warren, C. E., and 0. E. Davis. 1971. Laboratory stream research:
objectives, possibilities, and constraints. Ann. Rev, of Ecol.
Syst. 2:111-144.
Warren, C. E. , 3. H. Wales, G. E. Davis, and P. Doudoroff. 1964.
Trout production in an experimental stream enriched with sucrose. 3. Wildl. Mgmt. 28(4):617-660.
Waters, T. F.
1961. Standing crop and drift of stream bottom
organisms. Ecology 42(3): 53 2-537.
Wustenberg, D. W, 1 954. A preliminary survey of the influences
of controlled logging on a trout stream in the H. 3. Andrews
Experimental Forest, Oregon. M. S. Thesis. Oregon State
College, Corvallis. 51 pp.
54
Wyatt, B. 1959. Observations on the movements and reproduction
of the Cascade form of cutthroat trout. M. S. Thesis. Oregon
State College, Corvallis. 60 pp.
APPENDICES
55
Appendix A.
Tagging sitesa and numbers of trout tagged during 1972 and 1973. Tagging dates
are pooled into bimonthly intervals.
Interval
Oct. -Nov. 1972
Mar. -Apr. 1973
May-June 1973
July-Aug. 1973
a
See Figure 1 for locations of tagging sites.
Site
1
Number
47
2
26
3
8
4
25
5
45
7
29
2
105
3
18
5
127
6
13
2
100
3
29
5
207
6
40
2
9
3
10
5
4
6
7
Appendix B. Method employed to correct mark-and-recapture estimates.
During the 2-mo interval between sampling periods, several of the required assumplions for
mark-and-recapture estimates were not met. Scar tissue on a few recaptured trout indicated some
tags were lost. Tagged trout, particularly those near ends of study sections, may have emigrated
and been replaced by untagged trout. Occurrence of these events would have caused a decrease in
the number of tagged trout, M, beyond that expected by natural mortality. This would have resulted
in an incorrect ratio of the number of tagged to the total number of trout in the sample at t2, the
second sampling period. This ratio (or its reciprocal) could not be corrected since the Bailey modi-
fication of the Petersen equation requires addition of one to both the number of trout captured, C,
and the number recaptured, R, forming a slightly modified ratio. A corrected M (M*) was calculated
and substituted into the modified Petersen equation. M* is the number of trout tagged at t1 (M)
minus the number of trout lost from the section because of failure to meet all necessary assumptions
for mark-and-recapture estimates. Thus, M* is an estimate of the number of originally tagged trout
still in the study section at time t2, not subtracting those lost to natural mortality.
To estimate M*, a least squares regression line was fitted to the logarithm of the ratio of the
number of tagged to the total number of trout captured during successive sampling periods. The
logarithmic transformation provided a linear fit to the data. It was unknown which factors might
affect the rate of decrease of this ratio, so separate lines were fitted for each combination of year
class, study section, and tagging date (Figure A). If there were no loss of tags or tagged fish, the
lines would have a slope of zero.
The regression lines provided data necessary to calculate M*. The ratios of the number of
tagged to total number of trout at t and t2 were estimated from the regression equations. The
number of tagged trout, M, at t1 was available from tagging data. By simple proportion M* was
calculated. An example of this method is included in Figure B. Whenever M was a mixture of trout
tagged both in April and June, M* was calculated separately for each tagging date and summed for the
Bailey equation (Table A).
Ratios of the number of tagged to total number of trout at time of tagging
were estimated by extrapolating the regression lines back to that time (Figure A). This method is
conceptually similar to that employed by Parker (1955) to correct Petersen mark-and-recapture
estimates for effects of recruitment. For this study the number of tagged fish was corrected, whereas
Parker corrected the ratio of tagged to total fish in the population.
57
70
60
.50
.40
30
0
C's
10
.05
1971 0
1970+ V
.01
10
Airi1' June ' Aig.
1973
Figure A.
o&.
tc.
Ajri1
Jlne 'AtEg.
1974
Decline in the ratio of number of tagged to total number of trout from April 1973
to October 1974. Data are presented for each combination of year class, study
section, and tagging date.
58
V
2OF
.
I
4
Unshaded
0
April tagging
r
10
08
50
40
30
20
10
0
05
01
April
1973
June
Aug.
Oct.
Dec.
Feb.
1974
April
Figure A (Continued)
June
Aug.
Oct.
59
Assumptions not met resulting in
decrease of tagged trout by 50
Assumptions met
........ 1000
Population size at t. 1000
Population size at t1
Tagged trout at t1 (M) ..... 500
Tagged trout at t1 ( M) ....... 500
Number captured at t2(C). .
Number captured at t2 (C)
500
Recapturesatt2(R) ...... 250
A
N=M
L)
R+1
. . . .
500
Recaptures at t2 (R ) ....... 225
500 (501)
251
= 9981
M*
M
Ratio2
Ratio
=
A
N
500 (.45)
50
=450
M*(C+1)_ 450 (501)
R+1
226
9981
1See Ricker (1958, p. 84) for discussion of the Bailey formula for unbiased estimates.
Figure 8. Illustratiye example of method employed to correct mark-and-recapture
estimates. Natural mortality has not been included to simplify the
example. Fifty percent of the population was captured at t and t2.
Table A.
Study
section
Estimates and data for the mark-and-recapture methods of estimation from April through
October 1973. Ratios are estimates of number of tagged to total number of trout as shown
in Figure A.
Year
class
Ratio
Tagging
date
M
C
t
R
Ratio
t2
M*
N (95% C. I.)
April estimates
Unshaded
1972
April
June
a
Total
1971
1970+
Shaded
1972
27
0
27
0.204
62
24
0.270
0
62
0
April
June
63
Total
63
April
June
Total
April
a
0
139
84
0.178
55.0
55.0
0.265
60.8
60. 8
24
275(185-365)
207 (140-273)
June
Total
1971
April
Jui
1970+
21
13
0
0
Total
21
April
June
Total
84
0
84
80
0.131
0.127
20.4
13
30
20.4
0.606
0.417
118 (64-172)
57.8
0
90
57.8
30
155(114-195)
June estimates
Unshaded
1972
1971
April
June
Total
April
June
Total
1970+
April
June
Total
Shaded
1
57
58
188
25
106
131
26
43
69
0
b
b
28
28
0.236
0.171
14
67
0. 178
0. 162
0.491
0.437
154
81
0.265
0.394
68
13
22
35
0.261
0.318
1
41.3
42.3
276 (18S..366)
22.7
94.3
117.0
221(189-254)
25.6
34.7
60.3
115(90-141)
1972
April
June
Total
a
1971
April
June
13
8
0.127
0.123
12.6
58
71
36
0. 373
0. 357
55. 5
Total
1970+
April
33
June
41
96
68.1
44
18
21
39
0. 417
0.243
0.305
0.224
Total
74
101
aTrout too small for tagging at time of capture; binsufficient data.
147(116-178)
24. 1
37.8
61.9
158(120-195)
61
Table A. (Continued)
Study
section
Year
class
Tagging
date
M
R
C
Ratio
Ratio
t1
t2
M*
N (95% C. I.
19.8
19.8
210(120-300)
21.6
58.4
80.0
199(160-238)
August estimates
Unshaded
1972
April
June
Total
1971
0. 171
24
15
66
90
43
0.162
0.437
17
June
23
Total
40
1972
April
June
Total
a
1971
April
June
Total
1970+
April
June
Total
0
17
17
April
1970+
Shaded
April
June
Total
0
28
28
190
146
0.121
0.146
0.387
58
15
15
0.261
0.318
0.257
0.254
16.7
18.4
35. 1
68
30
9
6
0.123
0.120
8.8
34
0. 357
0. 343
32.7
83
20
26
0.305
0.224
91
21
14
3S
43
29
23
52
aTrout too small for tagging at time of capture.
0.226
0.203
78 (58-98)
41.5
129(90-169)
21.5
20.8
42.3
108(81-135)
62
Unshaded
[53
1972
20
341
1972
40
0
442
0
20
I Q1
60
636
40
20
40
80
120
160
200
Trait length (mm)
Appendix C. Length frequency distributions for trout captured in the unshaded and shaded
study sections during 1973. Arrows irilicate approximate divisions between
year classes.
63
Shaded
April
n = 123
20
1970+
-J1Tfl-{haN. -
i
- I
1971
20-
June
n=21O
ug.
0
i= 293
41
0
I
)ct.
= 368
40
80
120
Trout length (mm)
Appendix C (Continued)
160
200
Appendix ID. Evaluation of flushing method of stomach content sampling.
Trout
length
(mm)
Number
Number prey in
syringe sample
2-5
Prey length (mm)
Number prey remaining
in gut
>5
0-2
2-5
trout in
sample
0-2
56- 62
5
16
76
15
0
4
95-102
5
51
234
42
0
5
125-132
5
32
iSO
74
0
160-187
5
5
28
12
0
>5
Percent prey flushed
from gut
>5
0-2
2-5
100
95
94
0
100
98
100
5
8
100
97
90
0
11
100
100
52
1
65
100
bti
C
60
Cd
C)
1
C)
0
>
20
12
24
36
48
60
Time (hrs)
Appendix E. Volume of initial stomach contents remaining after increasing intervals
of time. Experiment was conducted in water temperatures ranging
from 14. 0 to 15. 4°C, and the curve fitted by inspection.
1
1
12
U
0
10
CS
5)
a
5)
a
Cd
V
May
June
July
Aug.
Sept.
Appendix F. Weekly mean water temperatures for the unshaded and shaded study sections during 1973.
Oct.
Nov.
Bars indicate the weekly range.
0'
Appendix G. Estimates and data for the removal method of estimation from April through October 1973 and for October 1974.
Year class
Shaded
Unshaded
Year Month
1973 April
1973
First catch
Second catch
N
First
1971
4
44
3
23
16
16-16
95% C. L
June
1972
92
catch
28
Second catch
A
N
131
118-145
95% C. L
Aug.
First catch
Second catch
N
Oct.
1974
Oct.
151
140-162
8
16
68
19
1
10
20
86
9
23
75-89
66
13
82
76-87
31
64
10
18
13
44
88
89
78-98
74
20
133
56
14
64
31
11
3
21
34
194
155
53
32
243
195
223-263
122
38
176
160-190
180-208
186-204
173
69
17
85-94
77
20
101
103
91-110
94-112
14-20
113
61
80
67
53
73
33
12
29
28
159
75
124
112
20
83
96
145-172
105-142
70-81
54
12
14
83
94
81-107
74
64-74
163-183
69
70-88
95
0-54
35-53
72
64-80
42
9
53
49-58
89-136
38
9
50
44-55
67-99
1971+
84-106
8-10
39
167
95% C. 1.
29
60
141
First catch
First catch
Second catch
113
1971
9
22-47
N
95% C.1.
40-120
1970+
1972
1971+
22
95% C. 1.
Second catch
85
1970
1973
18
88-104
47
10
59
54-64
-1
Appendix H.
Comparison of weight prediction equations by method of Ostle (1963). Significance
at 0. 01 level indicated by double asterisks.
F statistic
(d. f. in numerator and d. f. in denominator)
Equations coinpareda
All five
17.52**
(8 and 415)
All unshaded
12. 88**
(4 and 229)
April and July unshaded
0.42
(2 and 137)
July and Oct. unshaded
23. 40**
(2 and 182)
July and Oct. shaded
28. 16**
(2 and 186)
July both sections
6. 26**
(2 and 182)
Oct. both sections
5. 95**
(2 and 186)
a
See text for explanation of dates and sampling locations.
Appendix I.
Weight prediction equations from data collected during 1973. Equation employed
for April, June, and August in the unshaded section is from the combined April and
July data for this habitat.
Study
section
Unshaded
Shaded
Date employed
Equation
April, June, Aug.
log10W
Oct.
log10W = -5. 0869 + 3. 0357 log10L
April, June, Aug.
log10W = -4. 6797 + 2.8481 log10L
Oct.
log10W= -4. 8526 +2. 9131 log10L
-4. 8608 42.9455 log 10L
Sept., Oct., and Nov. 1972
Unshaded
20
1971
1970
N
89
1969+
1972
Sept., Oct., and Nov. 1972
1971
20 -
Shaded
n = 143
1969+
1973
60
0
1.4
40
'
1.4
ct-t
i97
40
20
Trout length (mm)
Appendix J.
Length frequency distributions of trout captured in the unshaded and shaded study
sections during the fall of 1972, 1973, and 1974. Arrows indicate approximate
divisions between year classes.
70
I (V7
40
20
0
0
V
'-4
1974
Oct. 1974
I
1
40
I
1973s4/
80
Shaded
1972
n239
120
Trout length (mm)
Appendix J (Continued)
160
200
Appendix K.
Analysis of variance of daily instantaneous growth rates for tagged and untagged trout of the 1971 and 1970+ year classes. Factors for
the 2 x 2 x 3 design are year class, tagging status (tagged and untagged), and time of year. Blocks are the unshaded and shaded study
sections. Significance at 0. 01 level is indicated by double asterisks.
Source
Total
d,f.
M.S.
F
23
Blocks
1
9, 600
Year class
Tagging status
1
110,433
.4066
16.1783**
Time of year
Year class x tagging status
Year class x time of year
Tagging status x time of year
3-way interaction
2
6, 600
223, 606
2, 091
72, 162
0. 9669
32. 7580**
0. 3063
11. 1576**
Error
Appendix L.
1
1
2
2
2
11
6,514
0.9543
6, 818
0. 9988
6,826
Analysis of variance of daily instantaneous growth rates for all trout except the 1973 year class from the unshaded and shaded study
sections. Factors for the 3 x 3 design are year class and time of year. Blocks are the unshaded and shaded study sections. Significance
at 0.01 level is indicated by double asterisks.
Source
Total
d. f.
M. S.
F
17
Blocks
1
22
Year class
2
388, 756
0. 00210
37. 0773**
Time of year
Year class x time of year
2
318,103
30.3389**
4
87, 626
8. 3573**
Error
8
10,485
72
Appendix M.
Estimated production and calculations for the unshaded and shaded study sections from
April 1973 to April 1974. The 1971 year class could not be identified in April 1974.
Therefore, in October 1973 the 1971 and 1970+ year classes were combined forming
the 197 1+ year class.
Unshaded
Year
class
Computation
interval
Mean
length
(mm)
Mean
weight
(g)
1973
July
35.00
0.49
Growth
rate
N
Stock
biomass
(g)
446
218.5
243
376.6
208
626. 1
300
864. 0
255
1048.1
A
1.15516
October
54.70
1.55
April
65.00
3.01
April
64.00
2. 88
0.66758
1972
0. 35574
June
72.21
4.11
0.48789
August
85.22
6. 69
225
1505. 3
197
1394.8
130
1198.6
270
3067.2
221
3222.2
190
3171. 1
162
2598. 5
148
4518.4
0.05678
October
90.32
7.08
0. 26320
1971
April
95,00
9.22
April
102.00
11.36
0.24906
June
111.00
14.58
August
116.22
16.99
October 118.22
16.04
0. 13536
-0. 03985
1970+
April
142. 67
30.53
0.08265
June
146.73
33.16
112
149.50
35.04
90
1971+
36. 14
October 129.75
21,28
73
2638. 2
235
5000.8
130
3157.7
0. 13235
April
132.00
24.29
Total
Total on basis of surface area of water (g/m2)
343.8
501.3
334.7
956. 1
340. 1
1276.7
622.9
1450.1
82.3
1296.7
341.3
3144.7
783.2
3196.7
432.7
2884. 8
-115. 0
4116.1
340.2
3433.7
189.1
2895.9
89.5
4079. 3
539. 9
3153.6
0.03091
October 154. 50
297.6
3713.9
0.05508
August
Mean
biomass Production
(g)
(g)
4324. 7
7.5
73
Appendix M (Continued)
Shaded
CompuYear
class
tation
interval
Mean
length
(mm)
1973
july
29.00
Mean
weight
(g)
0.31
Growth
rate
A
N
Stock
biomass
(g)
286
88.7
124
136.4
81
153. 1
170
251.6
146
359. 2
127
534.7
112
487. 2
76
418.0
152
863. 4
128
1001.0
110
981.2
96
787. 2
160
3636.8
128
3165.4
108
2572. 6
1.28311
October
47.92
1.10
April
55. 00
1. 89
April
50.44
1.48
0.53894
1972
0.50839
June
60. 30
2.46
August
72.84
4.21
October
76. 72
4. 35
April
80.00
5.50
April
80.92
5. 68
0. 53818
0.03178
0.23533
1971
0.31865
June
90.50
7.82
August
94.78
8.92
October
95. 39
8. 20
131.64
22.73
0.13155
-0. 08359
1970+
April
0. 08463
June
135.61
24.73
August
133.83
23 82
October 135.37
22.74
92
2092.1
October 116. 30
14. 61
188
2746. 7
-0. 03761
-0.04653
197 1+
0. 14231
April
118. 50
16. 84
Total
Total on basis of surface area of water (g/m2)
106
Mean
biomass
(g)
Production
(g)
112.5
144.3
144.7
78.0
305.4
155.3
446.9
240.5
510.9
16.2
452.6
106.5
932.2
297.0
991.1
130.4
884.2
-73. 9
3401. 1
287. 8
2869.0
-107. 9
2332.3
-108.5
2265, 9
322. 5
1785. 0
1488. 2
2. 6
74
Appendix N.
mpe..Iiiou
eta. dt..t Sy yeor eln.a during 197L
2t
era indicated aa true.' (tr) IC cancr eon ..s 1eCC than or eqool to
0.12. Annollda were prnpurtion.d .quaily btwecn aquatic and terCeS
trial since oriltin wua unknnwn. Adult Dlptcr,.. excluding Chironneidat
and Tipulidu.. were ciaceifted us trrrctrtal.
P,rcntnto
(
Parch 223O
1972
1971
7.4
2.6
0.6
0.3
8.9
1.0
14.3
5.4
3.1.
4.1
5.9
10.4
25.9
1.1
21.4
1970+
1972
tiiatut Aqustle tosette
Ephemeropter
2pa.arus
8aeis
A1etus
6.3
Zp.ered1a
arairototh2e.b4a
Other Epheeeroptera
7ocjl
?lecoptera
heneropcara
3.1
30.7
iieoeridae
1.2
9eitcperlidae
Teeniopterygidas
3.3
Perlidee
Pettodtdac
1.8
te
9.1
tr
Chlotoperiidse
total. Plecoptera
P.hyacophilidae
C1oaaosooatjdae
Bydropsychidac
20.1
45.7
6.8
10.8
9.9
0.2
67.3
76.4
Thlopotaaidae
Chironosidas
Sieulidae
6.1
29.7
10.6
24.3
3.6
3.1
29.7
0.2
41.9
9.1
0.2
4.6
5.9
6.8
6.1
16.8
11.0
46.3
50.7
14.3
2.0
0.3
0.3
Tipulidse
Dixidat
8lepharecerida
Other Diptera
Total DiDtsrC
30.3
3.3
4.2
Psychoe.yidae
tdostoaatida
Icachycentridac
Calaaoceratida.
TrieSoptera pupae
Total Triehoptera
Oipteta
31.1
9.1
24.4
9.0
1.0
11.)
6.0
2.8
0.2
14.6
ttichoptera
U.anapSi1idae
10.1
tr
46.3
52.7
83.1
100.0
2.3
ir
20.5
13.8
13.2
2.3
4.6
0.9
3.3
17.3
1.8
3.3
19.7
14.0
100.0
78.2
100.0
100.0
100.0
100.0
it
Toc*1 MegaloDteta
Coleoptera
Dytiscidne
iiydrophi1ida
Zleidaa
total Coleoptara
Total I tare Aquatic
Adult Aquatit Irrsaca
Chironceudue
tiputtda.
£phtmerrcpt era
Plucoptera
13.9
tric1opter*
Coleoptera
Total Adult Aqtatic
Other Atuacia
Anphipda
ialmooidae
13.9
0errco.3a
Copepoda
iT
Cast ronoda
A'-.ncij.Ja
Tte1 Other Aquatic
Tot*l P.quatic
Terrestrial
CotIcnSots
97.0
100.0
100.0
1.7
78.2
15.3
9iynencptera
6.4
Coleopt.ra
Iioc.optcra
Chticpoda
flipltpt4a
enrrc1 Ida
Arachnlda
Othcr Tc:reatra1
Total ?cs'rentrlat
Total weight o
tty (g)
ItiUed
itch in sanpic
oC finS 1onttS se)
1.3
3.0
0.0231
7
54-66
21.8
0.3894
7
86-118
0.3747
5
129-150
0.OjlO
0.0219
3
3
d935
78-43
0.112?
8
502-152
75
Appendix N (continued)
Un.hud.d
1aaCure Aquatic tn..cta
taoeroptett
tpQrua
a.t1s
A.eeiet
e:..tla
Paraieptap!Zebia
AprIl 21
1972
1971
63.4
14.3.
31.3
6.4
14.7
3.9
1.2
2.3.
33.4
53.3
39.6
0.4
32.1
73.5
29.4
1.7
2.3
0.3
11.1
2.0
26.0
10.5
19.3
40.2
73.5
33.3
3.4
5.5
4.0
0.4
3.6
1.7
5.7
0.3
8.1
5.1
4.1
4.6
1970+
19/2
27.6
2.4
6.6
1971
0.4
3.3
1970+
9.3
1.6
13.3
0.9
6.6
3
Other £eercptera
Total Cphee.roptera
?leeopter*
NeOuridae
1.0
teuctrida
tttoper1i4a.
'raeniopterygida.
Parlidae
Petlodidas
Chiaraperlidac
Total Plecoptera
Trichoptera
Rco;hit1dae
Closaosoo.at idea
Bydtopaychidae
10.3
Psychoayida.
Phi1opotaidae
l4nmephilida,
Lepidoatonatida.e
Erechyctatridee
CalaeGc.tztjdaa
Trichoptera pupae
Total Trichoptara
Diptera
Chitonoeida
Siaulidae
Tipulidee
Other Oiptera
Totil Diptera
)St9.al*ptera
CT
0.4
2.4
Cr
CT
Cr
3.4
12.4
14.1
1.3.7
2.7
4.3
2.7
6.8
0.2
4.6
tr
tr
.5
Cr
2.7
14.1
5.8
100.0
99,4
99.6
9.0
0.8
0.3
3.8
0.4
0.3
Cr
D1.xidaa
8lepaarocerS4ae
14.6
0.4
2.3
20.7
1.6
1.3
6.1
2.3
Cr
5.0
11.6
94.6
1.3
1.3
98.6
Sialidee
Total iegalcpcera
Coleopcera
DytiscLdee
Hydrophilidac
!1eidae
Total Calaoptlra
Total Iaaator Aquatic
Molt Aquatic tiaacta
Chironoeldac
CT
Tipulidac
pheaeroptera
?lacopcera
Tticlto9tert
0.3
1.1
0.4
0.2
1.3
Caleoptera
Tta1 Mull Aquatic
Other AquatIc
Iunphipoda
Saiaonidae
Xncaphus
Ostracoda
Copepcda
Cetiopoa
Anncltda
Total Other Aquatic
Total Aquatic
Terrestrial
C?
100.0
99,4
tr
100.0
94.6
99.9
Co11esto1a
8yaetoptara
C?
Cø1eoptra
5.4
Roaopt era
Neaiiptera
Chilopeda
tflpIopoda
Annc11!a
Arachnids
C?
Cr
Clhet Terreetrial
Total Terreetrial
Total wciCht at idootIlied
prey (p)
)luabcr fia La sanpIe
Eange oC
ia
len8th isis)
0.0410
3
64-81
Ct
3.5
0.6
tr
3.4
ti
0.1860
1.0399
0.0241
1.4951
4
93-100
Cr
0
173-152
0
1
7G-.'lOA
13
110174
308-162
10
73-106
4
52
1
124-158
8
86-120
6
0.2
tr
0.2
2.2
0.3
1.6
0.9
0.3262
0,4346
2.2497
0.6260
0.0092
80
faa)
1
le,ti
fich of
Ran
eanple in (Iah Number
0.0368
Cr
identified
o
(g) prey
otht
Total
Terrestrial Total
rrnriot
Other
ArcPnid.a
Annclida
Dipiopo.da
Ch1ipoLa
flcnipteta
1.6
0.4
0.2
li000pcera
Ooleoptara
Diprera
lyaeneptera
Colleabola
Terreetrl.al
0,4
Cr
6.5
12.3
2.9
tr
tr
99.1
0.2
0.2
98.4
100.0
99.7
0.2
0,2
97.8
100.0
Cr
It
Aquatic Total
Aquatic Other Total
Anctelida
Caattopoda
Copepoda
OetTaco4a
ASOaphus
Salaonidae
Aaphtpo4a
Li
2.2
1.6
1.3
28.4
10.2
3.3
2.3
5.4
3.9
25.2
0.3
5,1
tr
3.3
0.3
334
5.9
0.3
97.9
97.8
92.0
86.3
tr
2,2
3.3
4.8
3.2
3.3
CT
Aquatic Other
Aquatic .4ult Total
Coleoptera
.hoptera
0.9
0.9
floptera
0.2
0,9
2.2
0.5
U..4
1.4
100.0
96.9
Cr
!phemeroptera
idac Tipul
Chttoncmidae
1aseta Aquatic Molt
Aquatic Iaaacure Total
Coleoptera Total
Uydrophilidae
tr
Cr
1.2
5.3
0.8
1.6
0.3
1.8
1.0
3.3
0.4
19.9
6.7
1.1
0.6
1.2
4.3
2.1
24.6
1.4
Oytiacida.
Coleoptera
flaealeptata Total
Sialidee
eta
Dtptera Total
DIptera Other
0.8
$iepharoceddae
flixida.
Tipulidae
7.6
Simulidae
3.0
Chirnoel4ae
Diptera
Triehoptet. Total
puaa Trichoptera
CL1aaoceratdge
8T4yentridae
0.5
t4pido$toeatidaa
LJ.aeepflfl.idae
Taeoiopcerygidaa
1.2
2.2
1.8
Pltilapotanidat
Pychcwyide
Udropeychidaa
idaa Clos$oaoaa.
61yacophiiidae
Trichoptara
Plecoptera Total
CMoroperlidae
Perlodidac
12.0
13..S
34.6
45,4
1.6
6.6
4.1
23.7
42.7
tr
13.7
1.1
0,2
23.1
6.4
27.7
0.3
1.5
6.5
4.2
2.1
17.3
2.9
26.1
23.6
?erlidae
4.3.
27.9
94.6
33.3
17.3
41.0
?eitoperlida.
23,6
Leuctridac
Reaoud4a.
2'latoptera
64.9
Epheacrcptera Total
Epheacroptera Other
Pae'a1cptoph,e.j4
tr
3.3
1.7
10.0
19.3
1.2
7.3
3..)
13.9
7.6
31.5
2.2
3.8
1.7
1.2
3.7
22.2
9.4
10.6
Zphe.re11a
Aaelecus
4.9
1.1
Ba.tis
CinygauLi
Zpeorvs
43.4
Zpharopt.ra
tna.cta Aquatic
1970+
1971
_Lrd
!atute
l97O.
1971
1972
__________________________
1472
tnuei) fount
II
?.ppMiz
76
111164
0.3
0.2
1.9
0.3
2.5
ir
0.4
it
7.5
5.3
0.1201
0.7426
2.2358
2
6
55-72
74-104
7
10.1
134143
3
0.7946
0.8
94-121
8
1.7836
2.4
66-75
4
0.1477
(nee)
0.4
tr
0.3
icngth fish at Linga
anepl. o (tah 1laber
(t) prey
Identified at knight Total
Tcrrestr5aj tutal
Terresttdal Other
Atachndda
Anaclida
0.2
0.5
Dp1opoda
9.8
U
Chilopode
Hcniptera
0.3
0.7
it
1.3
Dpter
tr
0.2
92.5
94.7
tr
Boopteta
Cteoptera
0.3
U
7.2
4.0
6.2
89.9
99.2
3.8
0.5
97.6
0.3
3.3
99.6
:r
tr
Byannoptera
Colleebnia
terrestrial
Aquatic Total
Aquatic Othet Total
Ann.lda
Gaatropoda
Copepoda
Ostraoda
3.3
tr
2.9
.lSCaphus
3.0
8.2
0.3
83.3
2.3
2.3
88.4
0.3
0.3
0.9
1.9
1.1
2.9
0.4
1.1
0.5
2.3
0.3
0.8
1.9
tr
89.9
0.2
0.2
S&leonidae
phipoda
Aquatic Other
Aquatic Adult Total
Coleoptera
tTichopteta
?lecoptera
6.8
!pheaieroptera
Tipullnat
Crdaa
1.4
92.4
94.3
0.6
91.4
0.6
tnsata Aouatc Adult
Aquatic lature total
Coleoptara total
!laidae
ydruphi1idae
Dyticidaa
14.1
7.0
14.5
8.7
26.3
4.3
9.8
0.3
16.0
0.4
0.2
0.6
5.4
1.2
0.3
2.4
7.2
2.2
44.4
31.8
2.1
0.6
1.1
1.1
1.5
0.6
6.0
1.6
4.9
0.5
1.2
7.0
14.1
Coleoptaro
Megaloptera Total
2.4
2.4
ega1otera
21.0
U
12.2
12.)
8.0
1.3
1.9
3.1
14.0
10,8
8.4
0.2
4.4
0.3
tr
3.5
13.9
13.0
Diptera Total
Diptera Otbat
Siepbaroceridae
Dixidae
Tipulldaa
Slauli4ae
3.9
iLl
tr
Cbironqotida.
Diptera
Trichoptera total
pupae Trehoptera
Celaocratidae
1.3
0.2
2.3
5.3
0.9
U
Pbi1potaoidae
?zychoyidae
0.5
10.6
3.7
0.6
6.3
4.2
1.7
tr
2.6
0.5
tr
14.3
1.3
0.3
0.3
2.3
4.7
10.4
43.2
8r.chicentridae
Lepideetcoatidac
LXinepki1idae
0.6
6.8
10.1
13.0
17.5
0.7
3.7
3.)
1.2
3.8
1.9
29.0
2.2
8.3
0.2
2.3
1.1
14.7
4.2
1.6
Bydropsychida.
Cloaaosacidae
U
1yacophl1idae
Trieboptera
PlecQpttra Total
Chioropertidae
P*rlodida.
Perlidae
Teeniopterygidea
?eltoperltdae
3.4
0.3
6.7
0.3
Leuridc
er
55.3
2.4
13.5
58.3
4.7
tr
14.2
9.9
2.0
26.3
10.3
2.3
28.4
4.9
23.9
2.6
2.3
6.3
7.4
0.1
0.6
5.6
76.3
9.3
eaourtdze
era Plecopt
£pheeroptsra Total
Ephiatopeita Other
ParLL.ptnphIebAa
Sp..erella
4.9
21.5
Ameletus
24.1
5.9
10.0
Zpeorus
lphee.eroptara
Tnaecee Aquatic Xaacure
l97+
1971
1912
t914
2971
1972
tIn.kd
19
My
(otttinued) M Appendix
77
78
Apendiz M (conc
inue)
lure 2
1972
1771
19704
1572
1911
ttote '.quattt Insecta
15704
3phea*ropcera
£peOrUS
10.7
15.2
33.3
Cinqu1e
8a.t.s
Aa91eeu5
3pe.te11a
5.1
Other Epheeroptere
Total Tpheeroptera-
33.7
5.3
L2
6.3
12.7
9.0
14.3
19.2
31.5
ParaZeptophlo.bie
?1eopteta
20.2
62.9
3.6
37.6
21.8
77.8
50.0
73.7
0.2
2.3
2.3
teuctridac
Peltoperl1dae
Taeniopteryidaa
?arUdae
Ptrlodldae
C11aroper1dae
0.5
total Plecopteta
0.3
0.6
0.8
Zacopht1idae
0.7
0.3
7,4
er
Trieboptera
Giooaoeat Ldae
tr
4.2
0.2
1.6
tr
0.4
0.6
Li
16.4
9.9
17.7
0.3
tr
0.7
Lh
Bydropsychidae
Paychotd
Philepotaatda.
ttephi1idae
5.0
2,1
0.3
LepidostoatatUae
8rschyceotr4e
7.7
0.3
0.9
CeLaeoceracidoe
Ttichopera pupae
Total trichopreza
Dipteri
Cir000aidae
Siulidae
Tipulidac
Dizid.ae
3lepharoceridae
Other Diptera
Total Dipera
ea1optera
Stalidee
total flegaloptera
0.3
0.3
12.8
14.0
2.8
3.5
r
3.2
3.9
1.2
4.2
3.9
0.6
30.0
13.1
35.4
2.2
2.6
0.6
1.2
0.4
1.3
8.4
9.1
0.8
15.0
24.6
1.6
0.3
24.1
tr
0.3
3.0
0.3
1.2
tr
3.7
0.7
2.1
2.9
0.3
0.3
Coleopterz
trjriacidae
Rydrophilidac
11.*idae
Total Coleoptera
Total leaature AquatIc
Adult Aquatic Insecta
CironotUdag
tipi1idae
95.6
83.8
0.3
*eegtoptera
Plecoptera
64.6
99.2
48.0
39.7
0.3
0.4
0.9
25.0
37.6
13.6
19.6
21.6
23.6
51.6
42.1
0.8
0.4
tr
0.8
0.4
100.0
35.6
trtchopcera
Coleopcera
total Adult .quatIc
Other Aquatit
0.5
kaphtpcda
Sal oidae
aphua
Oatratoda
tr
Copepodo
0.9
Oaatropoda
.4neiida
Total Other AquatIc
Total Aquatic
Tarteetrial
It
tt
tt
96,2
86.8
90.3
It
Couleabola
!yocooptora
1.0
It
100.0
tr
Diptera
0.5
5.1
8oaoptcra
Beolptcra
It
C1opoa
3.1
4.7
It
1.7
3.8
It
0.1
1.0
2.8
3.0
0.4
6.1
0.2
Dip 1070d0
Atathfda
Other Terreattfal
total Tarrcsrial
Total vct of
prey (7)
Nuaber HOh 1.
drcItfjod
aae,ld
Range of f1th linth Ceo)
It
3.8
0.0922
5
78-77
It
It
13.2
9.7
0.3192
1
106-122
3.7
0.7
0.6
0.1053
3
139-1I3
14.4
0.0133
0.0250
1.1451
2
3
10
59-63
84100
1101'1
79
Appendix N (continued)
tature Aquttic Ineecta
Epheia.roptera
£p.atu3
Cinygaula
3deC15
0.7
4.7
0.3
7.9
2.1
2.8
31.8
40.0
1.2
12.2
0.4
3.1.
16.5
12.4
1.6
14.2
2.3
54.3
6.1
0.9
37.6
3.9
0.7
7.9
0.3
4.6
21.4
0.7
0.6
2.0
0.9
AZeCos
Xpheei.reLZ
8.1
0.6
24.2
20.1
46.1
28.2
Pardloptop41.ehiâ
Other EpheTeroptera
Total Epheeeroptera
?lscuptera
Weour1da.a
75.7
0.4
?eltoperilda.
4.2
50.9
1.4
0.4
2.
TL*neptirygidae
Perlida.
Petlodidse
Chloroperlidae
Total Plicoptera
14.3
8.2
2.1
14.3
9.3
2.6
4.4
0.5
7.1
1.1
0.6
1.1
3.0
Trihoptera
ThlCtophilidae
G1es000nti4ae
N7drepsychid
Paychonyidae
Philopetanidee
25.1
5.3
0.3
2.4
L1anphi1idae
Lepidostonatidee
4.0
0.7
Tipo1id.
0.4
11.1
tr
3.7
3.1
17.3
10.6
30.2
2.3
17.2
3.3
0.3
Cr
0.2
6.3
4.3
tr
0.3
28.6
18.8
2.3
0.3
tr
2.3
0.3
12.7
32.1
11.6
4.1
7.1
3chycttridae
alaaocetatidae
Trichoptera pupae
Total Trichoptera
Dipteri
Chironooldee
Sixulidat
0.9
2.1
Cr
llepharocatidae
Other Diptra
Total Diptra
0.6
5.3
0.3
2.7
2.6
1.1
2.7
1.5
1.3
1.4
1.6
3.2
91.7
80.1
63.9
84.7
85.1
46.1
0.7
1.3
1.2
3.1
1.1
7.1
1.3
2.4
11.2
}CeZalopt era
Sislidse
Total Megaloptera
Col*optera
Dytiscidee
Hydrophilidea
Elaida.
Total Coleeptera
Total lature Aquatic
Adult Aquatic inOetta
Chircoeiidae
Tipulidac
Epheneroptera
Plecoptera
Trichoptera
Coleoptera
Total Adult Aquatic
Other Aquatic
Amphipoda
Salmonidse
Ascaphus
Ostracoda
Copepoda
0.3
5.2
0.3
3.2
Cr
Cr
Cr
92.2
tr
83.4
63.3
2.7
0.6
15.1
6.3
1.4
1.4
12.1
1.7
33.2
-
0.4
Gatropoda
Annejida
rocal Other Aquatic
total Aquatic
Terrestrial
Colleabola
flysenoptera
CC
1.5
4.6
Diptera
Coleoptera
Honnptrra
iptcra
0.4
97.2
0.2
10.7
0.8
1.1
1.0
tr
7.8
1.4.6
17.8
1.2
87.6
0.7
3.0
1.0
0.5
0.4
0.8
10.6
2.3
12.4
33.2
90.6
0.9
2.6
5.7
0.2
CM1opod
Diplopoda
Arue1Id.i
Arochnida
Othct
rcstria1
otal TertestriaC
TOCa1 ohc o
identf ted
prey (g)
Nuahot (ieh to sampLe
Ranpe o
1nh 1006th (mm)
0.1151.
7
60-83
0.3687
6
104.120
34.7
0.0770
2
133-134
0.1213
6
61-72
0.0820
4
60-100
9.4
0.3010
5
112151
AppeOdtZ N (continued)
July 5
1972
Uiidd___________________________
1971
1970+
1972
1971.
1910+
1.0.4
tr
1.5
17.1
15.6
1.3
2.4
taturt Aquatic Insects
!pheseroptera
Epeorus
2.3
tr
8a.tls
48.0
10.1
CJngau1a
.*,.ietoa
6.1.
pbeezeiia
Pra1eotoph1ebia
Other Ephceroocera
Teo1.
hem optera
?3ecopera
1.5
53.3
0.4
0.9
U.S
Nemuurida.
L.a.
d.ae
20.9
1.9
9.3
Ch!croperlidae
Total P1ocopces
9.3
Pe1o.t4ae
?rchopcera
R2yacophi3ide
Gloesosomatida.
0.3
22.8
36.5
0.4
0.3
0.2
8.4
25.4
4.2
0.3
8.3
2.4
13.2
1.0
1.4
8.8
13.6
0.3
10.0
21.2
0.3
1,2
12.8
0.1
1.0
0.3
tr
tr
Peltopetlidae
l'seoiopterygidae
?eylidae
8.!
t
)Tydopsyehidae
Psychosyidse
Plopotan.idae
Liepbi1ida
0.3
0.3
Lepidostomatidac
achycentrida.
Cs1accerstida,
Tri.choptera pupae
1.0
19.5
t
0.3
0.3
14.2
9.6
0.3.
Totil Trichoptera
5.2
5.3
11.1
22.3
21.2
22.3
20.7
44.0
Chironoisida.
7.9
2.2
1.7
9.3
0.3
3,9
0.9
1.9
2.4
0.2
9.8
0.3
7.5
2.2
Diptara
Sioujidse
Tipulidae
Dizidas
!lepharoceridae
1,0
Other DLptera
LO
8.9
total Oiptera
0.3
2.7
2.7
73.2
73.2
98.3
0.8
1.1
4.2
Sislidae
Total flea1optera
Coleopter.a
Dytiscids
8ydrophi2id
tImida.
total Coleopteta
total Immature
Adult Aquatic Ir.sect
uat.
Tipuildas
Ephaaieropters
Plecoptera
Trichoptera
Ooleoptera
Total Mult Aquatic
Other Aquatic
32.0
49.3
71.5
59.2
52.?
1.3
0.3
3.7
1.2
7.6
2.2
1.6
12.0
3.4
0.2
1.9
0.7
9.7
2.4
7.3
19.6
tr
1.6
0.6
tr
1.6
3.9
4.5
92.2
3.0
3.0
0.9
9.1
kaphipoda
SalsonIdae
Ascaphus
Ostrsco4a
Copepoda
Castropada
Annelija
Total Other Aquatic
TotaL Aquatic
terrestrial
0.1
91.9
98.5
51.9
CollenboL
flyeenoptera
Olptera
Coteopcera
Nomotera
)*eodptera
Chilopoda
Dip1oodo
1.7
0.9
3.5
1.4
24.1
0.9
23.1
86.3
1.8
4.7
6.3
0.6
0.8
1.8
Anne114
Arachnids
Other Terrestrial
TotaL Tertestrtal
Total ..eight o( Identified
prey (g)
Nusbor of fish In sample
Lingo of fish Ie.igth ()
tr
0.1
3.1
1.3
0.0688
0.0790
3.0697
3
3
7
71-80
104-115
48.1
l)514)
13.7
0.0786
3.9
1.3
7.3
0.0734
5
3
6171
52l02
61.1
0.3
2.)
31.7
0.7
0.4
0.3
2.4
19.3
0.1973
7
111171
81
Appendix N (concir,ued)
Jull 20
I!...!, ,,i.4
1973
1972
1971
1970+
1972
1971
1970+
Xsture Aquatic Insects
Epheneroptera
Epeorus
3.etis
Ae2.tus
tpMa*:eJJa
61.1
0.6
1.9
4.3
Para.Zeptophlebia
Other Epheeeropcara
Total EphemCroptera 68.2
Piecoptera
8.0
t
31.0
10.0
1.7
43.7
0.1.
9.0
1.3
11.8
95.4
0.3
0.9
0.7
1.1.7
14.5
2.7
4.7
72.6
Nes.ouridae
Leuctridac
Peltoperlidae
Taeniopterygidae
Perlidae
Parlodidae
chloroperlidae
Total Plecoptera
Trichoptera
Lepidcon.stidae
8racbycentridaa
Ca1aaocerti4ae
Tichoptera pupae
Total Trichoptera
Dipt era
31.2
Tlpulidae
Dixidse
Slepharocerida.
Other Diptera
Total Diptera
Xea1ept era
20.7
4.0
0.3
12.9
2.3
1.3
1.9
26.4
30.3
3.0
0,1
2.9
3.8
4.0
tr
4.8
4.3
0.2
0.3
1.6
18.5
1.9
1.0
3.6
5.8
15.5
25.5
tx
13.2
2.8
1.7
22.2
20.4
1.0
2.7
3.3
0.6
0.9
It
It
3.1
01
0.2
6.8
9.1
2.3
1.7
0.2
0.3
9.3
tr
0.2
Lienaphilidae
Sisulidas
13.2
3.7
0.2
21ryacophiUda.
Glosaosonatidse
8ydropayehidae
Paychonyidae
?hilopotarnidae
Cbirenosidae
6.0
1.1
1.3
8.6
7.1
7.1
40.3
1.9.9
19.3
6.3
tr
tr
0.9
31.2
3.3
1.3
3.0
19.3
2.3
9.8
It
Sialidac
Total 14.galoptera
Coleopcera
0yLaci44e
4.2
ltydtephilidae
Total Colcoptera
Total tture 4quatic
Adult Aquatic Insetta
Chironoaida
Tipulidac
Zpheseroptera
99.4
98.3
4.3
49.1
0.6
3.4
Coleoptora
Total Adult Aquatic
Other Aquatic
61.1
0.5
?lecoptera
Tricbopttra
0.6
3.0
1.0
32.7
12.7
46.3
2.1
0.3
Kialdas
2.1
58.6
86.5
46.3
80.6
5.7
0.6
1.5
14.3
1.8
0.8
3.1
6.9
2.3
3.1
4.0
14.3
92.9
69.5
84.6
0.1
3.2
6.4
0.9
2.5
0.9
20.0
Aaç.htpoda
Saltor,idae
scaphua
Ostracoda
It
Cooepo..1a
1.4.3
Case ropoda
A Ida
Total Other Aquatic
total Aquit1c
100.0
Terrestrial
Colle*bola
Ryasnoptera
Diptera
Colcopteta
tr
99.4
0.6
Nonoptera
tr
62.5
tr
1.1.3
0.8
20.6
Heaipttra
60.0
6.3
7.3
5.7
12.0
It
8.1
0.3
4.5
2.0
IlUlopoda
06r 1;poda
Anncl.id.t
Ar4hnida
Other Terrectrial
Total ThrrestrAat
cipht of Idonctiled
y ()
'Total
Nu&,er fish In sample
Ran
0.6
0.0137
9
of fIsh jcntii (.a) 23-35
0J875
1
73-91
2.6
2.3
27.5
0.2381
6
103-130
0.5
32.0
0.2066
2
143
0.6
tr
It
7.1
0.0160
10.5
0.0323
4
3
56-72
33-98
15.4
0.2397
6
112-i 80
Appcndix N (continued)
Lin.sli,jth.d
1973
1972
1071
1910+
1972
Sded
1971
1970+
10.3
2.3
tr
24.6
4.8
7.7
Ir
taacur Aquatic maCeta
Eph...rept era
EpPorus
2.8
C1nyeu1a
8aeeis
A1.tus
ZpheaozelJa
PazaiepCapJ,lcbla
Other Ephemeropetra
motel Epieeropteta
?1ecopter
Neacurida.
Leucttidae
3.2
0.3
6.4
2.6
6.3
13.9
31.2
0.4
16.7
34.7
20.4
34.4
39.8
2.3
9.1
tr
Peltoperlidae
Taenioptery*idae
?trlidaa
3.1
Pariodidae
Cbloroperlidae
4.0
4.0
Total ?lecopt.ra
Ttichoptera
Thyacophilida.
Clo,*oscciatidae
0.6
3.3.
1.0
1.1
U.8
Rydropsychi.dae
?eyehooyidae
0.3
?h1.lupot&mada.
LianepbiUdae
tr
1.2
3.8
1.1
23.9
20.3
30.9
2.3
4.3
4.9
3.3
32.6
2.0
2.0
11.2
2.0
2.6
1.2
0.8
tr
2.0
3.7
0.4
0.3
0.3
tr
Ir
Trichoptera pupa.
Total Triehoptera
Diptera
Chironoeidae
Tipulidee
Diaidae
flephareceridac
Other Diptera
Total Diptera
NealopCere
24.2
10.6
0.3
Stautida.
0.6
11.0
Lapidosta..atdaa
Brachyceotrldae
Csiaooceratidae
0.7
12.3
2.1.
2.2
0.6
2.6
tr
1.3
10.8
tr
0.3
1.3
Stalidaa
Total Negaloptera
Coleoptera
DTtiseidae
Hydrophilida.
0.3
0.3
1.7
E3aidae
Total Coleoptera
Total Denature Aquatic
Adult Aquatic Insecta
0.3
0.3
68.3
46.4
17.4
14.9
35.4
41.1.
3.3
2.6
3.1
0.9
2.0
21.2
1.3.
2.0
3.8
2.1
0.9
3.4
0.3
0.4
1.1
2.6
0.4
0.4
0.3
0.2
3.6
27.1
2.4
21.6
0.2
0.3
tr
21.6
93.5
0.2
41.1
0.3
80.2
18.3
62.3
tr
Rymenoptere
3.1
2.8
18.1
1.1
It
Nomopter.
Hemiptera
Chilopoda
Dipiopoda
0.6
0.6
31.6
0.3
0.6
11.9
7.6
8.2
4.7
1.4
3.8
17.0
7.6
19.8
48.1
81.5
CKttoneatdae
tipulida.
!pheaeroptera
Plecoptera
Trichoptera
Coleoptera
Total Adult Aquatic
Other Aquatic
0.8
2.1.
Aaphipoda
SaDeonida.
Ascaphus
Ostracoda
Coppoda
0.3
0.4
CeetrOpoda
Terrestrial
Collesbola
Diptera
Coleopeers
4.3
14.4
0.3
Aanelida
Total Other Aquatie
Total Aquatic
8.1
tr
1.4
43.5
tr
46.6
2.6
1.3
9.7
0.3
17.9
68.1
8.1
4.1
0.7
Annul Ida
Arachnida
0.3
Other Terreatrial
Total Terrestrial
Total ueight of idealif led PCCy ()
Number fish in saaple
6.1
0.0616
8
Sange of Ifnh length (na) 33-49
52.9
0.1587
6
78-100
0.9
0.0369
0.2493
3
4
105-130
140-163
6.3
0.4
1.1
37.5
96.3
82.1
0.0238
5
64-78
0.1878
0.1065
4
6
93-106
131-173
110-13).
6
0.2298
94.106
4
0.3173
74-95
S
0.0264
143-134
4
1.0429
19.7
19.7
tr
9.1
3.3
1.7
33.7
33.7
0.1
Cr
0.4
23.1
85.7
12.1
3.8
31.1
0.5
19.9
05-132
4
0.0734
51.6
80-91
7
0.0566
7,3
46-54 () 1enth fish of 8ang.
3
aunpt. Ia ftab bet
(;)
0.0503
10.1
4.4
0.2
pity
Cleat- of ht
ifled
total
TorreatrL1 Total
Trroatr1e1 Other
p)
C)i1opoda
76.9
14.3
tr
Cr
9.9
1.1
68.9
1.1
11.6
0.2
1.7
80.1
.3
5.9
24.1
4.3
16.9
48.4
0.1
4.3.
0.7
2.3
92.8
0.5
aiptera
0.2
2.0
8.3
0.6
39.9
1,2
Bonoptera
Coeootera
Diptera
Byuenoprera
Col).embola
Tarreatricj
4qutic Total
Aquatic Ohar total
Annelida
Cr
G-.atropoda
Copepod*
25,3
11.0
1.1
9.3
0.1
0.3
Oatracoda
1.2
LiJpAu
79.3
S1iiOnidaa
Anphipnda
3.3
13.6
Cr
tr
0.9
56.1.
11.0
1.6
11.0
1.4
Cr
1.0
C?
14.7
14.4
15.9
18.9
2.2
1.3
Cr
1.2
Cr
0.3
Plecoptera
tpbeeeroptera
1.2
76.3
0.3
29.3
Cr
1.0
Aquatic Other
Aquatic Adult Total
Coleoptera
licbopttra
2.3
4.9
7.2
42.0
1.5
2.2
tipalidae
Chir000aidae
IrseCCa Aquatic Adult
26,3 Aquatic anature total
2.8
Coleopteri total
1.6
14.8
29.7
39.2
tr
2.8
0.3
Bpdrophilid.aa
Dytiacidee
Colaopteta
He;alopt.ra total
$iaiidae
-
0.9
C:
4.2
6.9
1.0
1.1
23.3
32.9
26.6
3.2
3.1
14.8
19.1
0.3
tr
25.8
Cr
tr
tr
38.7
9.9
8.3
6.9
3.1
0.7
11.8
1.0
0.2
6.4
Cr
CC
4.0
0.6
2.7
Cr
1,5.1
4.3
30.2
4.2
0.4
10.6
26.0
ega1optara
D1.xidac
Tipulida*
Si,1ida.
33.6
6.6
0.4
Cr
Cr
3.3
3.5
CC
tr
Dipteti total
Otptera Other
hroeerida. 31.
4.4
CC
Cr
6.4
tr
Cr
0.9
25.8
CC
2.6
4.0
2.6
0.2
C?
2.2
0.2
Cr
34.0
1.2
0.8
2.4
28.6
Chironojdaa
Diptra
trichoptera Total
pupae Triclioptera
Calaaoce:atidao
Idea chyccntt
tepidoatociatidas
Uznephilidae
PhiloocCaatdae
Paychoeayida.
Nydropsychidae
Glessosoeatjdae
11tyaeophilidae
era trichopt
Plecoptera Total
Chloroperlidae
Petlodi.iae
?erlida.e
Taen!optarJi4ae
Peltoperlidac
tuctride
Nroourida.
P1ecGptea
Ephenerptera Coca!
tphu.croptera Other
P1taleptop...Zebe
ZpMe.reZla
1.0
Spdzus
Epheneroptera
Ineecta Aquatic Iatura
1970+
1971
1973+
1972
1971
23_,,_
i.972
Jflhaded
August
1913
(continued)
N
Appendix
83
Appen4tz 2 (eont&nue.)
Scpteeher
8
1972
Uns..,thd
1973
1972
1971
19704
'97L
tature Aqu8tc táecta
1970+
Epbe.etoptcra
Zpeorua
Cnyg.ua
A1.tus
8peez.11a
Para1.ptophlebia.
Other Ephe.ropra
Total Epeeetopara
Plecopteta
0.5
0.2
9.0
9.2
1.9
8aetls
10.3
30.7
4.3
3.8
0.2
7.5
3.5.9
3.8
2.6
4.3
tr
tr
0.4
7.8
tr
4.4
8.6
3.4
7.9
21.9
9.5
1.3
4.9
0.9
0.6
0.3
Neouidae
Leuctrid.ae
1.4
Pa3.to'lidae
Teeniapterygidac
P.rlidae
2.9
3.0.0
Total Piecoptet.a
4.3
10.1
RhyaconhiUda*
1.8
?erlodidae
0.3.
0.9
tr
0.4
ChloroperUdaa
Trihoptera
GZoesoaoatida*
?eychooyida4
0.7
Leph11id4e
5.1
Leptde.toat2da.
1.9
0.2
U$repsyhi4a.
Thilpotealdae
1.3
29.0
1.1
2.7
8rayeotridas
Calaiioceratidae
Trichoptera pupae
total Trchopcera
9iptera
Chironøai.da
Silidae
Tlpulidee
DixIda.
81epharoeerdae
Other Dlptera
total Oiptera
24.8
1.6
0.6
5.1
12.7
29.3
1.1
2.7
33.3
26.7
1.6
30.4
1.9
4.8
tr
2.3
1.0
U
0.9
tr
0.3.
0.3
2.9
U
31.4
1.9
1.4
1.2
lotal tuature AquatIc 90.6
1.4
1.2
58.3
13.3
5,2
0.5
U
)feg1optcra
14.7
4.8
2.2
2.2
1.0
3.8
1.0
1.9
1.0
3.9
28.3
50.5
1'3.4
0.)
2.9
U
4.8
2.3
7.6
2.8
58.5
88.3
58.1
13.2
2.8
1.9
3.2.
34.3
0.1
25.9
3.9
SLe11.lae
total }ega1optera
Coleopteta
Dytscidaa
BydrophiUdee
E1i4ae
Total Coleoptera
Mull Aquatic. Iceecca
Cbirono.idae
Tipulidae
U
4.9
U
U
6.6
Plecoptera
tricioptez*
3.9
Coleoptere
total Adult Aquatic
Other Aquatic
0.9
15.7
2.8
0.7
3.9
U
0.6
0.4
0.3
0.6
0.6
62.6
14.2
It
1.6
16.7
58.5
/.ephipoda
Salaonidae
Aacaphua
Ostrece4a
Copepoda
Zr
Castropoda
Othet Aquatic
Total Aq.,atic
t'L.*t
Tttreatrlal
Col1ebela
96.9
U
Hyuenootara
Diptara
1.4
Co1eoptara
trptera
1.4
ChUopoda
Diplopoda
33.0
yr
3.1
1.0
0.3
$7.1
2.3
21.8
2.7
2.9
16.7
21.7
74.9
tr
1.7
1.5
2.0
4.8
6.0
A.zne1ida
Ar*chi3a
Other T'rreetrial
Total Turreetrial
Tot1 ieht o8 tdcta-
iftod prey ()
Wueor (ih
i
eop1e
8an;c o flch length(en)
0.3
3.2.
0.0898
$
81-53
0.2
yr
37,4
0.1209
3
79-100
85.3
0.0)84
4
104-117
9.2
78.3
0.O1
3
141-146
3,8
11.7
0.0h36
6
71-85
1.0
41.9
0.0105
3
98-106
0.3
0.7
86.6
0.0902.
6
114-165
II
AppCndtx H (continued)
S,Cbor 23
1973
X*Cuo-a Aquatio Ineecta
Epheacropters
peo:us
Iaeeis
tpheae:ella
Paralep phi ebia
Other Ephe-aeroptera
Total Epheaeroptara
3.972
3.971
1970-4
tr
0.7
8,6
0.7
0.5
9.2
19.7
10.2
2.4
10.8
0.3
3.9
29.6
6.0
11.0
1.0
23.6
1.4
0.2
9.1
4.3
0.3
13.3
1.1
?eltoperlidaa
31.0
13.8
14.8
5.4
0.4
0.2
2.3
6.3
3.910+
0.2
tr
0.3
0.3
0.6
1.9
1.0
4.8
Cr
0.2
0.3
13.8
2.9
34.5
0.6
23.6
0.9
23.1
23.3
0.9
0.3
38.5
0.9
25.0
0.3
24.3
?lecopc era
Neaourdoe
Leuctr1ae
1973.
0.2
1.6
0.2
Cr
4.9
tr
3.972
0.2
Taen1opCery4dae
Perlidee
Perlod1dee
Chloroperlida.
Total Ptecopteta
Trioheptera
EyacopMlidae
O1oa*000at1dae
Bydropeychidas
Psyehoayldaa
Pllopotaoidae
1.7
0.4
Lionephilidae
3.0
3.2
0.2
0.3
1.1
0.3
0.4
0.6
1.1
9.5
5.3
8.2
7.6
15.4
2.8
2.3
3.1
4.0
1.0
7.1
0.7
8.3
0.2
3.3
3.9
3.1.1
14.0
1.5
13.5
16.8
1.epidoetoaatid*.
Zrachyceotridea
0.2
Cr
3.6
3.5
23.4
15.8
Tpu1idae
1.4
Dtxidaa
1.2
alaooerat1da*
Trfohoptera pupae
Total Triohoptera
Dlptera
Chlronoiatdae
2.3
9.7
0.8
8.0
5.2
4.3.
1.)
1.5
0.6
8.2
1.2
8.0
Simuli4aa
8lepKzrceridaa
Other Dtptera
Total Diptata
2.9
21.2
Mea1opteEa
0.9
tr
0.8
Cr
4.1
3.6
3.3
Sialidae
Cr
Cr
Total Mea1optera
Coleoptera
DyCisc4ae
Bydrophilida.
Elmidie
Total Coleoptera
Total tature 414UaC1O
Adult Aquotlo Thacota
Choronoeldac
T1pul±dae
Epheocroptera
0.2
77.6
3.2
1.3
76.6
Cr
3.3
87.2
1.7
1.0
0.4
Cr
1.4
48.7
33.6
Cr
Cr
Cr
5,4
0.9
40.2
1.3
0.4
6.3
40.2
1.4
0.4
1.2
0.7
1.7
Plocoptra
TrichoDtera
Coleoptera
Total Adult Aquatt
Other Aquatt
1.3
0.2
43.4
13.3
Mphtpoda
Salaon6dae
tr
Asrap1i.'s
Oetraouda
Cop4pod
Catropoda
Mtoe1ia
Total (thcr Aquatie
Total AquatIc
Colleabola
Nyacooptera
Dfptera
0.2
Total TerreatreL
Total ,,c1ght of idunt-
Ifird prey (9)
9uaber (tab In suaple
Cr
Cr
LI
Cr
Cr
80.5
82.9
83.6
4.6
4.7
4.4
Cr
3.2
0.8
13.3
58.7
1.5
2.9
3.7
8.5
11.3
C1eoptare
Arachojie
Other Terrestrial
Cr
0.9
0.9
3.4
19.5
0.0590
3
85090 of flab 1enrh (oa) 4O-8
19.3
0.3
Cr
UcoLptera
Chilopoda
D1pJopo
Anneli,lu
Cr
tr
tr
87.3
17.4
18.7
48.3
0.7
54.7
1.0
0.7
0.6
tr
tr
3.1
4.1
0.2
0.2
tr
3.3
8,4
0.5
6.3
2.5
tr
2,1
1.0
0.2
17.4
9.2
80.7
3.2.7
17.1
0.2721
10
86-104
16.4
0.1784
2
104-133
0.0363
2
131-3.45
0.1744
4
67-93
34.7
6.1
0.2
-
31.2
0.2614
5
93-108
45.3
0.30(22
6
137-3.59
86
Appendis N (contiaucd)
13
173
1972
1911
1970+
1972
1971
1910+
toture Aquatic tnscct*
Ephemeropter.
Zpeorus
Cinvqaua
0.4
4.1
1.2
tr
Aae2etus
2.3.
Petal eptophlebla
0.1
EpA oai.rella
Other Ephemeroprara
Total EpheaetopCar*
Plecoptera
3.3.
7.2
Neaoridat
20.3
1.6
4.1
10.8
0.7
21.1
5.4
1.3
0.2
1.3
7.1.
1.2
L.euctrl4ae
S.4
6.7
2.3
15.9
2.3
8.2
14.9
tr
e3teper1idae
6.7
Taenlopcerygidae
?etUdae
Petlodjdae
ebloroperl Ida.
total 1ecaptera
18.0
1.3
trichoptere
tr
2iyacophi1idae
18.0
6.7
2.1.
C1ossoaaati4ae
Hydropychida
0.3
0.4
Psychoydae
?2i1opotanUdae
tiephili4a.
0.6
7..epidostooacida.
14.9
6.4
13.1
4.3
rachycentridae
CalaaoceratLdae
ttichoptera pupae
0.3
total Trichoptera
1.0
17.0
6.4
62.1.
11.8
41.3
0.9
1.1
D4pter*
Chirnoadd.,
Siaulidae
tpu1idae
31epharoceridae
Othet Diptea
Total Diptera
galoptexa
51.114..
total 1ega1optera
62.1
tr
1.51
5.0
t
0.9
6.8
2.7
12.?
42.4
tr
0.9
6.8
2.7
12.2
50.7
56.0
38.3
22.7
9.1
24.3
Cbironoidae
Tipulida.
0.5
2.1
tr
6.8
1.2
Ephemeroptera
5.6
74.9
39.8
46.7
46.5
31.0
Coleoptera
Dytiac1iae
ltydrophilidae
0.4
Elnd4ae
total Coleopter.
Total Iatur. Aquatic
Ad1t .quatic Insect.
Plecoptera
trichopteca
Coleoptera
tota.1 Adult Aquatic
Other Aquatic
0.4
Cc
3.4
0.2
2.2
6.1.
2.1
1.0
4.4
0.2
C.?
tr
tr
Ct
77.1
3.1
Amphipoda
Saisocidea
Ascaphue
O.tracoda
Copepod.
ettO9nda
Total Other Aquatic
Total Aquatic
Terreatrial.
Collembola
Ryeooptera
Diptera
Coleoptera
Beaipecra
0.?
tt
Oplopoda
Tot1 weight o Ident-
I(d prey ()
Puieber
iah in sspCe
Ct
Cr
32.3
50.3
38.8
99.8
35.7
15.3
1.3
tr
0.1
28.3
4.2
Cr
tt
8.0
2.3
0.4
2.9
5.3
3.3
43.7
thi1ood
Annlida
Atchnid
Other Terrestrial
Total. Terteatrial
tt
79.0
3.3
0.4
36.0
1.9
22.4
0.6
tr
26.1
0.4
2.4
0.8
Cr
3.4
1.6
2.3
19.4
44.3
24.?
0.2
2.3
10.9
Ic
21.0
3.0398
47.2
3.0536
2.1
0.2
39.5
51.3
0.1710
0.2
0.1440
0.0908
0.0088
O.O2
S
1
Rang. ot fich 1cn1th () 44-59
3
82-103
2
204-125
6
140-290
73-95
3
93-103
6
110-113
97
Appendix N (cent Irnw,J)
X.ture Aquatic Ziaaacta
Eph..ropt era
Xpeoruz
0.4
0.4
0.8
Cinyuia
LieCI.
Zplanere21a
Pazaeptop?.Zobi
Other Cpheeeroptera
Total pheuaropterx
Plecoptera
0.8
0.3
14.7
Cr
1.0
3.8
tr
16.3
2.3
0.4
tr
1.3
10.7
4.3
1.2
9.5
10.5
0.3
10.7
16.1
0.3
0.3
Cr
0.4
3.6
tr
15.9
13.9
RityacophiUdae
Ole oeoacidae
E)dropnyctidae
0.3
10.3
0.3
0.2
0.2
6.0
2.4
12.6
65.4
tr
Pe1chofyidae
Philopetan.idae
tr
Litephi1idae
0.8
3raehycentrida
Calaeocerat Ida,
0.4
tepi4ostomatida.
1.4
1.2
0.4
0.3
L.tuctriae
Peltoparlida.
1.3
7.9
1.6
0.3
Nemouridae
Tatoio9tery3id$e
Perlidee
Perlodida.
Ch1oroperii4a
Total Plecoptera
Trirbopeera
2.3
LI
Cr
8.7
10.3
trithaptera 7J*C
Total Trichoptera
1.2
13.1
13.0
71.4
12.0
4.6
5.6
3.4
1.6
1.0
0.4
1.3
0.6
0.4
13.9
20.0
25.9
0.9
8.4
Total 1uature Aquatic 47.4
4dglt Aquatic loaeta
39.0
26.1
1.1
1.5
6.0
2.9
2.2
Chir000aidae
S1uUdae
TipulIda.
Dix4ae
3lepbatocer±dae
Other Diptera
Total Oiptera
)tegaloptera
Stalid&e
Total 1ega1optera
Coleoptere
3.4
19.3
Cr
2.0
3.6
0.4
tr
0.4
0.2
1.3
2.4
4.8
1.6
6.8
26.2
46.6
1.2
1.2
0.3
0.2
29.4
3.8
3.1.3
20.4
1.7
13.3
45.1
33.8
33.7
91.7
31.0
1.2
0.4
1.0
0.8
32.3
Cr
0.4
Dtiacida.
lydrophilida.
Zlaidae
Total Co1eptera
C1irenonidae
Tipulida.
Epheaeropcera
?Iecopeara
25.3
10.7
Trichoptera
77.1
C
0.8
Cr
6.3
24.0
Coleopc era
Total Adult Aquatic
Other Aquatic
Mphipo4a
25.3
17.7
30.6
0.8
7.5
0.4
S*imoaidae
Catracoda
Cr
Copepoda
Ct
C?
Castrope.da
Anoelido
Total Ocher Aquatic
Total Aquatic
Terrestrial
)yaenoptera
2.8
2.8
tr
56.7
56.7
6.0
1.8
20.8
0.3
32.8
7.3
6.7
Dipteta
Ccleupcera
Hoaoptcra
tr
75.7
3.0
0.4
78.2
5.7
0.1.
1.5
13.1
4.0
tr
65.1
t
15.6
0.5
9.3
0.3
0.6
CblloCoda
Olpioroda
Anneltd
ArocittjcM
Other Terrearia1
totil Terrestrici
total uaII.t of Ident4Od prey
11.0
2.3
0.0231
43.3
0.0947
43.3
0.2072
J
(oaber fieh in snn1e
7
Pone ci Ctah tnth (mae) 50-42
tr
3.2
7.6
2.3
3
84-94
8
107-3.30
21.3
00266
2
141-163
0.3
3.8
66.3
0.0252
3
73-79
8.3
0.1200
7
92-101
19.6
63.0
0.5125
5
111.3.92